C161C

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

- ACD proportioning valve malfunction

- Damaged harness wires and connectors

- Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics

Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?

YES Go to Step 3.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart).
After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.

Q. Is DTC No. C161C set?

YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. ACD proportioning valve check.

Measure the resistance of ACD proportioning valve.

Standard value: 3.7 ± 0.3 ohms


Q. Is the check result normal?

YES Go to Step 4.
NO Replace the hydraulic unit. (Refer to Service and Repair). Then go to Step 8.
STEP 4. AWC-ECU connector, intermediate connector, proportioning valve
(for ACD) connector check: C-51, D-11, F-28

Q. Is the check result normal?

YES Go to Step 5.
NO Repair the defective connector. Then go to Step 8.
STEP 5. Check the wiring harness between C-51 AWC-ECU connector terminal No.1 and F-28 proportioning valve (for ACD) connector terminal No.3 and between F-28 proportioning valve (for ACD) connector terminal No.2 and body ground.

Check the power supply line for open or short circuit, and check the ground line for open circuit.

Q. Is the check result normal?

YES Go to Step 6.
NO Repair the wiring harness. Then go to Step 8.
STEP 6. Scan tool data list

Item 92: ACD proportion valve (Refer to data list reference table Data List Reference Table).

Q. Is the check result normal?

YES Go to Step 7.
NO Replace the AWC-ECU. (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST)). Then go to Step 8.
STEP 7. Check whether the DTC is reset.

Q. Is DTC No. C161C set?

YES Replace the AWC-ECU. (Refer to Twin Clutch-Sportronic Shift Transmission (TC-SST)). Then go to Step 8.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions).
STEP 8. Check whether the DTC is reset.

Q. Is DTC No. C161C set?

YES Return to Step 1.
NO This diagnosis is complete.