ACURA: 2010-12 BRAKES Collision Mitigation Braking System (CMBS)

2010-12 BRAKES

Collision Mitigation Braking System (CMBS) - MDX

COMPONENT LOCATION INDEX

Fig. 1: Identifying Collision Mitigation Braking System And Related Components (1 Of 2) Courtesy of AMERICAN HONDA MOTOR CO., INC.

2010 2010 Acura Acura MDX MDX

2010-12 2010-12 BRAKES BRAKES Collision Collision Mitigation Mitigation Braking Braking System System (CMBS) (CMBS) - - MDX MDX

Fig. 2: Identifying Collision Mitigation Braking System And Related Components (2 Of 2) Courtesy of AMERICAN HONDA MOTOR CO., INC.

GENERAL TROUBLESHOOTING INFORMATION

CMBS INDICATOR

When the system is normal, the CMBS indicator comes on for about 2 seconds after turning the ignition switch to ON (II).

The CMBS indicator comes on when the adaptive cruise control (ACC) unit detects a problem in the system.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

NOTE:

●

The ACC indicator indicates problems related with the ACC system and

the CMBS.

●

The CMBS indicator only indicates its system problems.

●

The CMBS works with related systems such as the VSA system. If these related systems have a problem, the CMBS does not operate. In this case, the CMBS indicator and the related system indicator come on.

Fig. 3: Identifying Multi-Information Display And CMBS Indicator Courtesy of AMERICAN HONDA MOTOR CO., INC.

When a problem is detected by the self-diagnostic function, the CMBS stops operating, turns on the CMBS indicator, indicates the problem on the MID, and stores the DTC.

CMBS OFF SWITCH

Press and hold the CMBS OFF switch for at least 1 second to turn the CMBS off and on.

CMBS INDICATION

●

If the system is OK, the CMBS indicator comes on for 5 seconds after turning the ignition switch to ON (II) with the CMBS OFF switch on.

●

When the system is activated, the word BRAKE is indicated on the MID and the warning buzzer sounds.

○

First stage, BRAKE indicator and buzzer

○

Second stage, BRAKE indicator, buzzer, light braking, and light seat belt tension

○

Third stage, BRAKE indicator, buzzer, strong braking, and strong seat belt tension

●

If the system stops operating because of a problem, the MID indicates the problem.

ACC UNIT

The ACC unit controls the brake and various driver warnings when the system recognizes the possibility of a collision.

The ACC unit has a self-diagnostic function. If the system detects a problem, it stops the CMBS, and turns on the CMBS indicator.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

CMBS INITIAL CHECK

The ACC unit turns on the CMBS indicator if the CMBS initial check is not completed.

NOTE: For proper CMBS operation, if the ACC unit or the VSA modulator-control

unit is replaced, do the CMBS initial check incomplete troubleshooting (DTC 100)

MILLIMETER WAVE RADAR

The millimeter wave radar calculates the distance between the moving vehicle ahead and your vehicle and detects the two vehicles speed differential.

The ACC unit receives this information from the millimeter wave radar.

The millimeter wave radar also has an error detection function, and it sends a signal to the ACC unit if an error is detected.

HOW TO TROUBLESHOOT DTCS

Check and clear the DTCs with the HDS.

NOTE: When both the ACC and CMBS indicators come on, do the ACC system

troubleshooting first (except DTC 100).

Before troubleshooting, check and note these items:

●

Ask the client about the conditions when the problem occurred, and try to reproduce the same conditions for troubleshooting.

●

If the symptom does not appear and the CMBS indicator does not come on during the test-drive, but troubleshooting is done based on the DTC, check for poor connections or loose terminals at all connectors related to the circuit that you are troubleshooting.

●

After the troubleshooting or repairs are done, clear the DTCs, and test-drive the vehicle under the same conditions as when the DTC occurred originally. Make sure the CMBS indicator does not come on.

●

The ACC system and the CMBS may sometimes stop working because of the environment (weather, road conditions, driving conditions, etc.). A DTC may be stored in these cases.

DTCs may be stored even when the system is normal:

NOTE: The ACC indicator will not come on, but the CMBS indicator does come on

when the following DTCs are stored.

DTC 88: Millimeter wave radar out of detection condition

The millimeter wave radar overheats, the power supply voltage for the millimeter wave radar is low, or there is a communication error between the ACC unit and the millimeter

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

wave radar.

DTC 95: Power supply voltage too high

DTC 96: Power supply voltage too low

DTC 97: CMBS offset cancel timeout

Extensive driving on a rough road or the ignition switch is turned to ON (II)/LOCK (0).

DTC 102: CMBS parking brake incomplete releasing

Parking brake not fully released, or driving with the parking brake stuck.

HOW TO RETRIEVE DTCS

NOTE: Make sure the battery is fully charged before you begin.

1. Make sure the ignition switch is in LOCK (0). 2. Connect the HDS to the data link connector (DLC) (A).

Fig. 4: Identifying Data Link Connector Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Turn the ignition switch to ON (II). 4. Make sure the HDS communicates with the vehicle and the ACC unit. If it does not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ). 5. Use the HDS to check for ACC DTCs. 6. Read and record the DTC. 7. Turn the ignition switch to LOCK (0), then wait for 10 seconds. 8. Disconnect the HDS from the DLC. 9. Do the troubleshooting procedure for the DTC.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

HOW TO CLEAR DTCS

NOTE: Make sure the battery is fully charged before you begin.

1. Make sure the ignition switch is in LOCK (0). 2. Connect the HDS to the data link connector (DLC) (A).

Fig. 5: Identifying Data Link Connector Courtesy of AMERICAN HONDA MOTOR CO., INC.

DTCs icon, and follow the prompts. 6. Turn the ignition switch to LOCK (0), then wait for 10 seconds. 7. Disconnect the HDS from the DLC.

DTC TROUBLESHOOTING INDEX

Adaptive Cruise Control (ACC)

Indicator CMBS Indicator 11 Left rear wheel

sensor signal error

o o

12 Right rear wheel

sensor signal error

o o

13 Left front wheel

sensor signal error

o o

14 Right front wheel

sensor signal error

o o

DTC Detection Item

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

20 Steering angle sensor

malfunction

--- o

21 Yaw rate sensor error o o 22 Yaw rate sensor center position revision value error

o o

23 Yaw rate sensor gain

error

o o

24 Yaw rate sensor

diagnose malfunction

o o

25 Yaw rate sensor

stabilizing malfunction

o o

26 Steering angle sensor

adherence failure

--- o

30 Brake light relay

circuit malfunction

o o

34 Master cylinder brake fluid pressure sensor circuit open/short

--- o

35 Master cylinder brake fluid pressure sensor center position error

--- o

36 Master cylinder brake fluid pressure sensor shift error

--- o

59 F-CAN B Communication

error

o o

60 F-CAN A Communication

error

o o

61 Millimeter wave radar

communication error

o o

62 Millimeter wave radar

sensor error

o o

63 Millimeter wave radar

aiming error

o o

64 CMBS operation error

(excessive operation)

--- o

88 Millimeter wave radar

out of detection condition

--- o

95 Power supply voltage

too high

--- o

96 Power supply voltage

too low

--- o

97 CMBS offset cancel timeout

--- o

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

100 CMBS initial check

o o incomplete 102 CMBS parking brake

--- o incomplete releasing 103 CMBS brake control

--- o prohibition 105 Dust or dirt on the

millimeter wave radar

--- o

107 Millimeter wave radar

aiming incomplete

o o

112 Lost communication

with the VSA modulator-control unit

--- o

113 Lost communication

with the gauge control module

--- o

117 Lost communication

with the steering angle sensor

--- o

199 Adaptive cruise

control (ACC) unit programming error

o o

NOTE: When both the ACC and CMBS indicators come on, do the ACC system

troubleshooting first (except DTC 100).

SYMPTOM TROUBLESHOOTING INDEX

Symptom Diagnostic procedure Also check for

CMBS OFF switch does not turn on/turn off (CMBS indicator does not change)

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). 2. Test the CMBS OFF switch 3. Do the gauge control module

self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

●

An open or increased resistance in the wire

●

A short in the wire

The MID does not indicate when the CMBS OFF switch is

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ).

●

An open or increased resistance in the wire

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

operated

2. Test the CMBS OFF switch

A short in the 3. Do the gauge control module

wire self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

The buzzer does not sound

●

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). 2. Do the gauge control module

self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

The buzzer does not sound when the CMBS OFF switch is operated

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). 2. Do the gauge control module

self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

The MID does not indicate with the CMBS operating

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). 2. Do the gauge control module

self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

The CMBS system operates frequently

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). 2. Check the millimeter wave radar. 3. Check the front radar cover for

warpage. 4. Check the wheel alignment.

Driving conditions, weather, environmental influence

The CMBS system

1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC Driving conditions,

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

operated without

INDICATION) ).

weather, environmental danger of collision

2. Check the millimeter wave radar.

influence

3. Check the front radar cover for

warpage. 4. Check the wheel alignment. 1. Adaptive cruise control (ACC)

system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM The CMBS system didn't operate

●

Driving conditions, TROUBLESHOOTING (NO DTC INDICATION) ). 2. Check the millimeter wave radar. 3. Check the front radar cover for

warpage.

weather, environmental influences

●

Undetectable environment

4. Check the wheel alignment.

CMBS indicator not come on

does

Do diagnostic the gauge function control (see module SELF-

self-

DIAGNOSTIC FUNCTION ). CMBS indicator not go off

does

Symptom troubleshooting

HDS does not communicate with the adaptive cruise control (ACC) unit or the vehicle

Troubleshoot the DLC circuit CIRCUIT TROUBLESHOOTING ).

(see DLC

Incorrect HDS software

SYSTEM DESCRIPTION

The collision mitigation braking system (CMBS) anticipates collisions and assists brake operation to reduce the impact on occupants and vehicle damage. The system works in combination with the E-pretensioners, which retract the seat belts in anticipation of impact.

CMBS OPERATION

●

Warnings are both audible (warning buzzer) and visual (MID)

●

Evasive action support and collision-speed reduction by brake control

(1) Approaching a vehicle ahead: The CMBS warns the driver by a MID indication twice, after that, it warns by a MID indication and buzzer

(2) Closer to vehicle ahead:

●

(3) Collision unavoidable: Warning by a MID indication and buzzer

● sound.

●

Warnings by a MID indication and buzzer CMBS aids perception and

sound. evasive action by using

● the sensory warning of

CMBS reduces collision speed to mitigate damage.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

sound.

MAIN FUNCTIONS OF CMBS

●

When a collision is about to happen and the relative speed (the speed difference from the object ahead) is greater than 9 mph (15 km/h), the system provides warnings (audible and visual) and brake control.

●

When approaching a object ahead and the distance to the vehicle is very close, the system provides the collision warning (1st stage) by MID indication and buzzer sounding.

●

When the closing distance continues to decrease and there is a high risk of collision, the system applies light braking (2nd stage) with the 1st stage warning.

●

When the system judges that a collision is imminent, the system activates emergency brake control and applies strong seat belt tension.

CMBS CONTROL

The CMBS is operated by the ACC unit. The CMBS has the following functions:

Obstacle determination function

The system determines the potential for collision by the distance from the vehicle ahead and the relative speed based on the millimeter wave radar and the predictable course calculated by the driving conditions (wheel speed and yaw rate).

Warning function

When there is a high risk of collision, the system sends warning directions to the gauge control module and warns by both audible and visual means.

Brake control function

When there is a high risk of collision, the system sends brake directions to the VSA modulator-control unit and controls braking action.

CMBS ACTIVATION CONDITIONS

The system might activate (warn the driver, apply the brakes) when it detects or encounters these situations:

●

Metallic projections on the road

●

Metallic manhole and drain covers

●

Signs and guardrails ahead

light braking.

Low overpasses and narrow gates

●

Approaching vehicles that are turning left or right

●

Passing slower vehicles ahead

The system might not activate (no warning or intervention) when it detects or encounters these situations:

●

Low-speed, heavy traffic (such as in a traffic jam)

●

Being cut-off by a slower vehicle

●

Approaching a vehicle stopped at an angle

●

Driving on curves

●

Approaching a bicycle or moped

●

Dirt or snow stuck on the front radar cover

●

Heavy rain or snow

When the CMBS activates, it sounds and feels just like ABS activation.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

●

Fig. 6: View Of CMBS System Description Diagram Courtesy of AMERICAN HONDA MOTOR CO., INC.

ADAPTIVE CRUISE CONTROL (ACC) UNIT INPUTS AND OUTPUTS

Fig. 7: Identifying ACC Unit 20P Connector Terminals Courtesy of AMERICAN HONDA MOTOR CO., INC.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Terminal number

color Wire

Terminal name

Description Signal

ACC brake operated or 1 WHT BRAKE DIAG

brake pedal pressed: battery voltage

2 YEL

Detects brake light relay activation

Ignition switch ON + B TECH

Detects ignition switch ON/OFF

(II): battery voltage (10 A)

signals

Ignition switch OFF: about 0 V

3 GRN SG Sensor ground

Less than 0.2 V at all times

5 GRN VCC Provides sensor voltage

Ignition switch ON (II): about 5 V Ignition switch OFF: about 0 V

6 BLK PRESS FR

Ignition switch ON (II): about 0.5-4.5 V Ignition switch OFF: about 0 V

7 PUR F-CAN B H

Detects the brake fluid pressure signal of the right front brake caliper

F-CAN communication B (high) circuit

---

8 ORN K-LINE

Sends signals

and receives scan tool

---

9 BLK GND

Ground circuit for the ACC system

Less than 0.2 V at all times

10 WHT F-CAN A H

F-CAN communication A (high) circuit

---

Ground circuit for the ACC Less than 0.2 V at all

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

11 BLK GND system times

12 BLK GND

Ground circuit for the ACC system

Less than 0.2 V at all times

13 WHT

+ B BACK UP (10 A)

Provides DTC memory voltage Battery voltage

Ignition switch ON

14 BLU PRESS FL

(II): about 0.5-4.5 V Ignition switch OFF: about 0 V

15 GRY WEN

Detects the brake fluid pressure signal of the left front brake caliper

Detects signal

the write enable

---

16 YEL BRAKE LAMP Drives the brake light relay

Ignition switch ON (II): battery voltage Ignition switch OFF: about 0 V

17 RED M/R TRX

Ignition switch ON (II): battery voltage Ignition switch OFF: about 0 V

18 PNK F-CAN B L

Communicates with the millimeter wave radar

F-CAN communication B (low) circuit

---

20 RED F-CAN A L

F-CAN communication A (low) circuit

---

CIRCUIT DIAGRAM

Fig. 8: CMBS - Circuit Diagram (1 Of 2) Courtesy of AMERICAN HONDA MOTOR CO., INC.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Fig. 9: CMBS - Circuit Diagram (2 Of 2) Courtesy of AMERICAN HONDA MOTOR CO., INC.

DTC TROUBLESHOOTING

DTC 20: STEERING ANGLE SENSOR MALFUNCTION

1. Check for VSA system DTCs with the HDS (see PUMP MOTOR ).

Are any DTCs indicated?

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

NOTE: Before doing this troubleshooting procedure, check the steering angle sensor installation (see STEERING ANGLE SENSOR REPLACEMENT ).

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

YES -Troubleshoot the indicated VSA system DTC(s).

NO -Go to step 2.

2. Clear the DTCs with the HDS (see General Troubleshooting Information ). 3. Turn the ignition switch to ON (II), then wait for 10 seconds. 4. Turn the steering wheel from lock-to-lock several times. 5. Check for DTCs with the HDS (see General Troubleshooting Information ).

Is DTC 20 indicated?

YES -Go to step 6.

NO -Intermittent failure, the system is OK at this time.

6. Check the CALIBRATION STATUS OF STEERING ANGLE SENSOR in the ACC DATA LIST with

the HDS.

Is NOT COMPLETE indicated?

YES -Do the VSA sensor neutral position memorization (see VSA SENSOR NEUTRAL POSITION MEMORIZATION ).

NO -Faulty steering angle sensor; replace the steering angle sensor (see STEERING ANGLE SENSOR REPLACEMENT ), then do the VSA sensor neutral position memorization (see VSA SENSOR NEUTRAL POSITION MEMORIZATION ).

DTC 26: STEERING ANGLE SENSOR ADHERENCE FAILURE

NOTE: Before doing this troubleshooting procedure, check the steering angle

sensor installation.

1. Check for VSA system DTCs with the HDS (see PUMP MOTOR ).

Are any DTCs indicated?

YES -Troubleshoot the indicated VSA system DTC(s).

NO -Go to step 2.

2. Check the STEERING ANGLE in the ACC DATA LIST with the HDS, turn the steering

wheel from lock-to-lock.

Do any value change?

YES -Faulty ACC unit; check for loose or poor connections. If OK, update the ACC unit (see ACC UNIT UPDATE ), then recheck. If the ACC unit was already updated, replace the ACC unit (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION ).

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

DTC 34: MASTER CYLINDER BRAKE FLUID PRESSURE SENSOR CIRCUIT OPEN/SHORT; DTC 35: MASTER CYLINDER BRAKE FLUID PRESSURE SENSOR CENTER POSITION ERROR; DTC 36: MASTER CYLINDER BRAKE FLUID PRESSURE SENSOR SHIFT ERROR

1. Clear the DTCs with the HDS (see General Troubleshooting Information ). 2. Watch the ACC indicator.

Does the ACC indicator go off?

YES -Intermittent failure, the system is OK at this time. Check for loose or poor connections.

NO -Go to step 3.

3. Press the brake pedal. 4. Watch the ACC indicator.

Does the ACC indicator go off?

YES -Intermittent failure, the system is OK at this time. Check for loose or poor connections.

NO -Go to step 5.

5. Check for DTCs with the HDS (see General Troubleshooting Information ).

Is DTC 34, 35, or 36 indicated?

YES -Go to step 6.

NO -Troubleshoot the indicated DTC(s).

6. With the brake pedal released, check the master cylinder brake fluid pressure

voltage (BRAKE P) with the HDS.

Is there about 0.5 V?

YES -Go to step 7.

NO -Check the VSA system.

7. Test the brake booster (see MASTER CYLINDER INSPECTION ). 8. Start the engine, then press the brake pedal with about 314 N (32 kgf, 70.6 lbf)

pressure. 9. Check the master cylinder brake fluid pressure voltage (BRAKE P) with the HDS.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Is there about 2.5 V?

YES -Go to step 10.

NO -Check the VSA system.

10. Check the brake switch signal (BRAKE SW (N.O.)) with the HDS.

Does the indication show ON when the brake pedal is pressed, and show OFF when the brake pedal is released?

YES -Check for loose or poor connections. If OK, update the ACC unit (see ACC UNIT UPDATE ), then recheck. If the ACC unit was already updated, replace the ACC unit (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION ).

NO -Go to step 11.

11. Check for DTCs with the HDS (see General Troubleshooting Information ).

Is DTC 60, 110, or 111 indicated?

YES -Troubleshoot the indicated DTC(s).

NO -Troubleshoot the brake pedal position switch signal circuit (see BRAKE PEDAL POSITION SWITCH SIGNAL CIRCUIT TROUBLESHOOTING ).

DTC 64: CMBS OPERATION ERROR (EXCESSIVE OPERATION)

NOTE: If the CMBS operates frequently, DTC 64 is stored.

1. Remove the front grille (see FRONT BULKHEAD COVER REPLACEMENT ). 2. Inspect the frame for warpage, and check the installation of the millimeter wave

radar and the main bracket.

Is the installation and the frame OK?

YES -Go to step 3.

NO -Reinstall the components correctly, or replace if damaged, then go to step 3.

3. Turn the ignition switch to ON (II), then wait for 10 seconds. 4. Aim the millimeter wave radar (see MILLIMETER WAVE RADAR AIMING ). 5. Clear the DTCs with the HDS (see General Troubleshooting Information ). 6. Press the MAIN switch ON. 7. Watch the ACC and CMBS indicators.

Do both indicators come on?

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

YES -Go to step 8.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.

8. Clear the DTCs with the HDS (see General Troubleshooting Information ). 9. Watch the CMBS indicator.

Does the CMBS indicator come on?

YES -Go to step 10.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.

10. Check for DTCs with the HDS (see General Troubleshooting Information ).

Is DTC 64 indicated?

YES -Check for loose or poor connections. If OK, update the ACC unit (see ACC UNIT UPDATE ), then recheck. If the ACC unit was already updated, replace the ACC unit, (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION )

NO -Troubleshoot the indicated DTC(s).

DTC 100: CMBS INITIAL CHECK INCOMPLETE

NOTE: The CMBS initial check function checks the communication between the

adaptive cruise control (ACC) unit and the VSA modulator-control unit.

If the CMBS initial check is incomplete, the ACC and CMBS indicators come on. For the CMBS to operate properly, always do the CMBS initial check after replacing the ACC unit or the VSA modulator-control unit.

1. Turn the ignition switch to ON (II), then wait for 10 seconds. 2. Watch the VSA indicator.

Does the VSA indicator come on?

YES -Troubleshoot the indicated VSA system DTC(s).

NO -Go to step 3.

3. Check for VSA system DTCs with the HDS (see PUMP MOTOR ).

Are any DTCs indicated?

YES -Troubleshoot the indicated VSA system DTC(s).

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

NO -Go to step 4.

4. Start the engine. 5. Select CMBS from the DRIVING SUPPORT menu, then enter the MISCELLANEOUS TEST. 6. Do the CMBS brake operation. 7. Watch the ACC and CMBS indicators.

Do both indicators come on?

YES -Go to step 8.

NO -The system is OK at this time. The CMBS initial check is complete.

8. Check for ACC system DTCs with the HDS (see HOW TO RETRIEVE DTCS ).

Are any DTCs except DTC 100 indicated?

YES -Troubleshoot the indicated DTC(s).

NO -Check for loose or poor connections. If OK, update the ACC unit (see ACC UNIT UPDATE ), then recheck. If the ACC unit was already updated, replace the ACC unit, (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION )

DTC 103: CMBS BRAKE CONTROL PROHIBITION

1. Check for VSA system DTCs with the HDS (see PUMP MOTOR ).

Are any DTCs indicated?

YES -Troubleshoot the indicated VSA system DTC(s).

NO -Go to step 2.

2. Clear the DTCs with the HDS (see General Troubleshooting Information ). 3. Watch the CMBS indicator.

Does the CMBS indicator come on?

YES -Go to step 4.

NO -The system is OK at this time.

4. Check for ACC system DTCs with the HDS (see HOW TO RETRIEVE DTCS ).

Is DTC 103 indicated?

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

NO -Troubleshoot the indicated DTC(s).

DTC 117: LOST COMMUNICATION WITH THE STEERING ANGLE SENSOR

1. Clear the DTCs with the HDS (see General Troubleshooting Information ). 2. Turn the ignition switch to ON (II), then wait for 10 seconds. 3. Check for DTCs with the HDS (see General Troubleshooting Information ).

Is DTC 117 indicated?

YES -Go to step 4.

NO -Intermittent failure. The system is OK at this time. Check for loose or poor connections.

4. Check for VSA system DTCs with the HDS (see PUMP MOTOR ).

Are any DTCs indicated?

YES -Troubleshoot the indicated VSA system DTC(s).

NO -Go to step 5.

5. Turn the ignition switch to LOCK (0) 6. Disconnect the steering angle sensor 5P connector. 7. Disconnect the ACC unit 20P connector. 8. Check for continuity between ACC unit 20P connector terminal No. 10 and steering

angle sensor 5P connector terminal No. 4, and between ACC unit 20P connector terminal No. 20 and steering angle sensor 5P connector terminals No. 2.

Fig. 10: Measuring Resistance Between ACC Unit 20P Connector And Steering Angle

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Sensor 5P Connector Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Check for loose or poor connections. If OK, update the ACC unit (see ACC UNIT UPDATE ), then recheck. if the ACC unit was already updated, replace the ACC unit (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION ).

NO -Repair an open in the wire between the ACC unit and the steering angle sensor.

SYMPTOM TROUBLESHOOTING

CMBS INDICATOR DOES NOT GO OFF

1. Turn the ignition switch to ON (II), then wait for 10 seconds. 2. Press and hold the CMBS OFF switch for at least 1 second to turn off the system. 3. Watch the CMBS indicator.

Does the CMBS indicator go off?

YES -The system is OK at this time.

NO -Go to step 4.

4. Clear the DTCs with the HDS (see General Troubleshooting Information ). 5. Turn the ignition switch to ON (II), then wait for 10 seconds. 6. Check for the adaptive cruise control (ACC) system, VSA, and PCM DTCs with the

HDS.

Are any DTCs indicated?

YES -Troubleshoot the indicated DTC(s).

NO -Go to step 7.

7. Start the engine, and wait for 2 seconds. 8. Watch the CMBS indicator.

Does the CMBS indicator go off?

YES -The system is OK at this time.

NO -Go to step 9.

9. Stop the engine. 10. Check for ACC system DTCs with the HDS.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Are any DTCs indicated?

YES -Troubleshoot the indicated DTC(s).

NO -Test the CMBS OFF switch . If the switch is OK, do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

CMBS OFF SWITCH TEST/REMOVAL/INSTALLATION

1. Remove the instrument fascia (see DRIVER'S INNER DASHBOARD TRIM

REMOVAL/INSTALLATION ). 2. Remove the screws and the CMBS OFF switch (A).

Fig. 11: Identifying CMBS Off Switch Courtesy of AMERICAN HONDA MOTOR CO., INC.

3. Check for continuity between the 6P connector terminals in each switch position

according to the table.

Fig. 12: Identifying 6P Connector And Switch Positon In Table Courtesy of AMERICAN HONDA MOTOR CO., INC.

2010 Acura MDX

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

Fig. 13: Identifying CMBS Off Switch 6P Connector Courtesy of AMERICAN HONDA MOTOR CO., INC.

4. If the continuity is not as specified, replace the CMBS OFF switch. 5. Use a diode tester between the 6P connector terminals in each switch position

according to the table. 6. If the diode test is not as specified, install the CMBS OFF switch in the reverse

order of removal.

ACURA

Wednesday, November 7, 2018

2010-12 BRAKES Collision Mitigation Braking System (CMBS) - MDX

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