[Previous] [Next]

DTC C161C: ACD Proportioning Valve System (Malfunction)










caution
  • If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

OPERATION


AWC-ECU controls ACD proportioning valve.

DTC SET CONDITIONS


The code is set when the current monitor value of the ACD proportioning valve solenoid is determined to be abnormal.

PROBABLE CAUSES



DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting .) After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.

Q. Is DTC No. C161C set?
Go to Step 3.
This diagnosis is complete.

STEP 3. ACD proportioning valve single unit check
Measure the resistance of ACD proportioning valve.
Standard value: 3.7 ± 0.3 Ω

Q. Is the check result normal?
Go to Step 4.
Replace the hydraulic unit. (Refer to GROUP 27 - Hydraulic Unit .) Then go to Step 8.

STEP 4. AWC-ECU connector, intermediate connector, proportioning valve (for ACD) connector check: C-46, D-11, F-16

Q. Is the check result normal?
Go to Step 5.
Repair the defective connector. Then go to Step 8.

STEP 5. Check the wiring harness between C-46 AWC-ECU connector terminal No. 1 and F-16 proportioning valve (for ACD) connector terminal No. 3 and between F-16 proportioning valve (for ACD) connector terminal No. 2 and body ground.
Check the output line and ground line for open or short circuit.

Q. Is the check result normal?
Go to Step 6.
Repair the wiring harness. Then go to Step 8.

STEP 6. Scan tool service data
Item 92: ACD proportional valve indicator current (Refer to service data reference table .)

Q. Is the check result normal?
Go to Step 7.
Replace the AWC-ECU.(Refer to .) Then go to Step 7.

STEP 7. Check whether the DTC is reset.

Q. Is DTC No. C161C set?
Replace the AWC-ECU.(Refer to .) Then go to Step 8.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)

STEP 8. Check whether the DTC is reset.

Q. Is DTC No. C161C set?
Return to Step 1.
This diagnosis is complete.