C161D

DTC C161D: Electric Pump Relay Circuit 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 operates the electric pump via the electric pump relay.

DTC SET CONDITIONS

The code is set when the electric pump relay coil side circuit is open or shorted.

PROBABLE CAUSES

- Electric pump relay 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. C161D set?

YES Go to Step 3.
NO This diagnosis is complete.
STEP 3. Scan tool actuator test

OK: Operating sound of the electric pump can be heard.


Q. Is the check result normal?

YES Go to Step 8.
NO Go to Step 4.
STEP 4. Electric pump relay single unit check

Check the electric pump relay.(Refer to Testing and Inspection.)

Q. Is the check result normal?

YES Go to Step 5.
NO Replace the electric pump relay. Then go to Step 9.
STEP 5. Electric pump relay connector, AWC-ECU connector check: A-26X, C-46

Q. Is the check result normal?

YES Go to Step 6.
NO Repair the defective connector. Then go to Step 9.
STEP 6. Check the wiring harness between A-26X electric pump relay connector terminal No. 3 and C-46 AWC-ECU connector terminal No. 20.

Check the power supply line for short or open circuit.

Q. Is the check result normal?

YES Go to Step 7.
NO Check C-47 intermediate connector. When no problem is found, repair the wiring harness. Then go to Step 9.
STEP 7. Check the wiring harness between A-26X electric pump relay connector terminal No. 1 and body ground.

Check the ground line for open circuit.

Q. Is the check result normal?

YES Go to Step 8.
NO Repair the wiring harness. Then go to Step 9.
STEP 8. Check whether the DTC is reset.

Q. Is DTC No. C161D set?

YES Replace the AWC-ECU.(Refer to Active Center Differential (ACD).) Then go to Step 9.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
STEP 9. Check whether the DTC is reset.

Q. Is DTC No. C161D set?

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