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Collision Mitigation Brake System (Cmbs): Diagnosis Acura RL II facelift

Collision/avoidance 2 illustrations ~1571 words

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

  1. Ask the client about the conditions when the problem occurred, and try to reproduce the same conditions for troubleshooting.
  2. 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.
  3. After the troubleshooting or repairs are done, clear the DTCs, and test-drive the vehicle under the same conditions as when the DTC was originally.
  4. 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 that may be stored even when the system is normal

DTC 88: ACC indicator does not come on, CMBS indicator comes on

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 wave radar.

DTC 95: ACC indicator does not come on, CMBS indicator comes on

Battery voltage is too high.

DTC 96: ACC indicator does not come on, CMBS indicator comes on

Battery voltage is too low.

DTC 97: ACC indicator does not come on, CMBS indicator comes on

Extensive driving on a rough road or the ignition switch is turned ON (ID/OFF.

DTC 102: ACC indicator does not come on, CMBS indicator comes on

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

Scheme 4

Scheme 4: How to Retrieve DTCs
  1. With the ignition switch is in LOCK (0), connect the HDS to the data link connector (DLC) (A) under the left side of the dashboard.
  2. Turn the ignition switch to ON (II).
  3. 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»(ref-348508-S35625078472009112400000) ).
  4. Follow the prompts on the HDS to display the DTC(s) on the screen. After determining the DTC, refer to «DTC TROUBLESHOOTING»(ref-348611-S25993596642009112400000) . NOTE: See the HDS Help menu for specific instructions.

DTC Troubleshooting Index

DTCDetection ItemAdaptive Cruise Control (ACC) IndicatorCMBS Indicator
11Left rear wheel sensor problemOO
12Right rear wheel sensor problemOO
13Left front wheel sensor problemOO
14Right front wheel sensor problemOO
20Steering angle sensor malfunctionO
21Yaw rate-lateral/longitudinal acceleration sensor malfunctionOO
22Yaw rate-lateral/longitudinal acceleration sensor center position revision value errorOO
23Yaw rate-lateral/longitudinal acceleration sensor gain errorOO
25Yaw rate-lateral/longitudinal acceleration sensor stabilizing malfunctionOO
26Steering angle sensor adherence failureO
30Adaptive cruise control (ACC) relay circuit malfunctionOO
34Master cylinder brake fluid pressure sensor circuit open/shortO
35Master cylinder brake fluid pressure sensor center position errorO
36Master cylinder brake fluid pressure sensor shift errorO

DTC TROUBLESHOOTING TABLE

Note. When both the ACC and CMBS indicators come on, do the ACC system troubleshooting first (except DTC 100).

DTCDetection ItemAdaptive Cruise Control (ACC) IndicatorCMBS Indicator
60Communication line errorOO
61Millimeter wave radar communication errorOO
62Millimeter wave radar sensor errorOO
63Millimeter wave radar aiming errorOO
64CMBS operation error (excessive operation)O
88Millimeter wave radar out of detection areaO
90A/T system and/or PGM-FI system malfunctionO
95Power supply voltage too highO
96Power supply voltage too lowO
97CMBS offset cancel timeoutO
100CMBS initial check incompleteOO
102CMBS parking brake incomplete releasingO
103CMBS brake control prohibitionO
105Dust or dirt on the millimeter wave radarO
107Millimeter wave radar aiming incompleteOO
110Lost communication with the PCM (PGM-FI system)O
111Lost communication with the PCM (A/T system)O
112Lost communication with the VSA modulator-control unitO
113Lost communication with the gauge control moduleO
115Lost communication with the SH-AWD control unitO
117Lost communication with the steering angle sensorO

CMBS INDICATOR REFERENCE TABLE

Note. When both the ACC and CMBS indicators come on, do the ACC system troubleshooting first (except DTC 100).

Symptom Troubleshooting Index

SymptomDiagnostic procedureAlso check for
CMBS OFF switch does not turn on/turn off (CMBS indicator does not change)Adaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Test the CMBS OFF switch (see CMBS OFF SWITCH TEST/REPLACEMENT ). Do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).An open in the wire A short in the wire
The MID does not indicate when the CMBS OFF switch is operatedAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Test the CMBS OFF switch (see CMBS OFF SWITCH TEST/REPLACEMENT ). Do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).An open in the wire A short in the wire
The buzzer does not soundAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
The buzzer does not sound when the CMBS OFF switch is operatedAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
The MID does not indicate with the CMBS operatingAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Do the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
The CMBS system operates frequentlyAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Check the millimeter wave radar. Check the front emblem for warpage. Check the wheel alignment.Driving condition, weather, environmental influence
The CMBS system operated without danger of collisionAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Check the millimeter wave radar. Check the front emblem for warpage. Check the wheel alignment.Driving condition, weather, environmental influence
The CMBS system didn't operateAdaptive cruise control (ACC) system troubleshooting (No DTC Indication) (see ADAPTIVE CRUISE CONTROL (ACC) SYSTEM TROUBLESHOOTING (NO DTC INDICATION) ). Check the millimeter wave radar. Check the front emblem for warpage. Check the wheel alignment.Driving conditions, weather, environmental influences Undetectable environment
CMBS indicator does not come onDo the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
CMBS indicator does not go offSymptom troubleshooting (see SYMPTOM TROUBLESHOOTING ).
HDS does not communicate with the adaptive cruise control (ACC) unit or the vehicleTroubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).

SYMPTOM TROUBLESHOOTING TABLE

DTC 20: Steering Angle Sensor Malfunction

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

  1. Turn the ignition switch to ON (II).
  2. Check for VSA system DTCs with the HDS. Are any DTCs indicated? YES - Troubleshoot the indicated VSA system DTC(s). NO - Go to step 3 .
  3. Clear the DTCs with the HDS.
  4. Turn the ignition switch to LOCK (0), then turn the ignition switch to ON (II).
  5. Turn the steering wheel from lock-to-lock.
  6. Check the DTCs with the HDS. Is DTC 73 indicated? YES - Go to step 7 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections.
  7. Check the CALIBRATION STATUS OF STEERING ANGLE SENSOR in the DATA LIST with the HDS. Is NOT COMPLETE indicated? YES - Do the steering neutral position memorization procedure (see «VSA SENSOR NEUTRAL POSITION MEMORIZATION»(ref-348550-S14170384032009112400000) ). NO - Faulty steering angle sensor; replace the steering angle sensor (see «STEERING ANGLE SENSOR REPLACEMENT»(ref-348550-S19097850032009112400000) ).

DTC 26: Steering Angle Sensor Adherence Failure

Note. Before doing this troubleshooting procedure, check the steering angle sensor installation.

  1. Turn the ignition switch to ON (II).
  2. Check for VSA system DTCs with the HDS. Are any DTCs indicated? YES - Troubleshoot the indicated VSA system DTC(s). NO - Go to step 3 .
  3. Check the STEERING ANGLE in the DATA LIST with the HDS, turn the steering wheel from lock-to-lock. Are any value change? YES - Faulty steering angle sensor; replace the steering angle sensor (see «STEERING ANGLE SENSOR REPLACEMENT»(ref-348550-S19097850032009112400000) ). NO - Faulty ACC unit; replace the ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(ref-348552-S13439405742009112400000) ).

DTC 34, 35, 36: Master Cylinder Brake Fluid Pressure Sensor Circuit Open/Short; Master Cylinder Brake Fluid Pressure Sensor Center Position Error; Master Cylinder Brake Fluid Pressure Sensor Shift Error

  1. Turn the ignition switch to 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? 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»(ref-348510-S17151465292009112400000) ).
  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»(ref-348552-S13439405742009112400000) ). 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 signal circuit (see «BRAKE PEDAL POSITION SWITCH SIGNAL CIRCUIT TROUBLESHOOTING»(ref-348529-S14693931382009112400000) ).

DTC 100: CMBS Initial Check Incomplete

Note. The CMBS initial check function checks the communication between the adaptive cruise control (ACC) unit and 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).
  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. Are any DTCs indicated? YES - Troubleshoot the indicated VSA system DTC(s). 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 forced 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. Are any DTCs except DTC 100 indicated? YES - Troubleshoot the indicated DTC(s). NO - Check for loose or poor connections. If OK, replace the ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(ref-348552-S13439405742009112400000) ).

DTC 103: CMBS Brake Control Prohibition

  1. Turn the ignition switch to ON (II).
  2. Check for VSA system DTCs with the HDS. Are any DTCs indicated? YES - Troubleshoot the indicated VSA system DTC(s). NO - Go to step 3 .
  3. Clear the DTCs with the HDS.
  4. Watch the CMBS indicator. Does the CMBS indicator come on? YES - Go to step 5 . NO - The system is OK at this time.
  5. Check for adaptive cruise control (ACC) system DTCs with the HDS. Is DTC 103 indicated? YES - Check for loose or poor connections. If OK, replace the ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(ref-348552-S13439405742009112400000) ). NO - Troubleshoot the indicated DTC.

Scheme 5

Scheme 5: DTC 117: Lost Communication With the Steering Angle Sensor
  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch to ON (II).
  3. Check for DTCs with the HDS. 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. Are any DTCs indicated? YES - Troubleshoot the indicated VSA system DTC(s). NO - Go to step 5 .
  5. Disconnect the dashboard wire harness 5P connector from the steering angle sensor (see «STEERING COLUMN REMOVAL AND INSTALLATION»(ref-348511-S08332992362009112400000) ).
  6. Disconnect the dashboard wire harness 20P connector from the adaptive cruise control (ACC) unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(ref-348552-S13439405742009112400000) ).
  7. Check for continuity between ACC unit 20P connector terminal No. 10 and steering angle sensor 5P connector terminal No. 2, and between ACC unit 20P connector terminal No. 20 and steering angle sensor 5P connector terminals No. 4. Is there continuity? YES - Faulty ACC unit; replace the ACC unit (see «ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION»(ref-348552-S13439405742009112400000) ). NO - Open in the dashboard wire harness; replace the dashboard wire harness.