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Acura RL. Manual - part 400

Fig. 11: Collision Mitigation Brake System Circuit Diagram (1 Of 2)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

2007 Acura RL

2005-08 BRAKES Collision Mitigation Brake System (CMBS) - RL

Friday, June 05, 2009 2:59:19 PM

Page 17

Fig. 12: Collision Mitigation Brake System Circuit Diagram (2 Of 2)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

DTC TROUBLESHOOTING

DTC 20: STEERING ANGLE SENSOR MALFUNCTION

1. Turn the ignition switch ON (II).

2. Check for VSA system DTCs with the HDS.

Are any DTCs indicated?

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

2007 Acura RL

2005-08 BRAKES Collision Mitigation Brake System (CMBS) - RL

Friday, June 05, 2009 2:59:19 PM

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NO - Go to step 3.

3. Clear the DTCs with the HDS.

4. Turn the adaptive cruise control (ACC) switch ON.

5. Turn the steering wheel left and right several times.

6. Watch the CMBS indicator.

Does the CMBS indicator come on?

YES - Go to step 7.

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

7. Check for DTCs with the HDS.

Is DTC 20 indicated?

YES - Check for loose or poor connections. If OK, replace the ACC unit (see ADAPTIVE CRUISE
CONTROL (ACC) UNIT REMOVAL/INSTALLATION ).

NO - Troubleshoot the indicated DTC.

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. Turn the ignition switch ON (II).

2. Clear the DTCs with the HDS.

3. Watch the adaptive cruise control (ACC) indicator.

Does the ACC indicator stay off?

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

NO - Go to step 4.

4. Press the brake pedal.

5. Watch the ACC indicator.

Does the ACC indicator stay off?

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

NO - Go to step 6.

6. Check for DTCs with the HDS.

Is DTC 34, 35, or 36 indicated?

2007 Acura RL

2005-08 BRAKES Collision Mitigation Brake System (CMBS) - RL

Friday, June 05, 2009 2:59:19 PM

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YES - Go to step 7.

NO - Troubleshoot the indicated DTC.

7. 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 8.

NO - Check the VSA system.

8. Test the brake booster (see BRAKE BOOSTER TEST ).

9. Press the brake pedal with about 314 N (32 kgf, 70.6 lbf) pressure.

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

Is there about 2.5 V?

YES - Go to step 11.

NO - Check the VSA system.

11. 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, replace the ACC unit (see ADAPTIVE CRUISE
CONTROL (ACC) UNIT REMOVAL/INSTALLATION ).

NO - Go to step 12.

12. Check for DTCs with the HDS.

Is DTC 60, 110 or 111 indicated?

YES - Troubleshoot the indicated DTC(s).

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

DTC 64: CMBS OPERATION ERROR (EXCESSIVE OPERATION)

1. Remove the upper grille (see UPPER GRILLE REPLACEMENT ).

2. Inspect the frame for warpage, and check the installation of the millimeter wave radar unit and the

main bracket.

NOTE:

If the CMBS operates frequently, DTC 64 is stored.

2007 Acura RL

2005-08 BRAKES Collision Mitigation Brake System (CMBS) - RL

Friday, June 05, 2009 2:59:19 PM

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