C161E

DTC C161E: Electric Pump Relay Circuit System (Stuck)

AWC PUMP RELAY SYSTEM CIRCUIT

Refer to C161D.

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.
- Since the fluid in the hydraulic unit will be hardened under low temperature, the load of the pump increases and the motor may not operate normally. Therefore, completely remove snow and ice from the hydraulic unit and leave the vehicle under temperature of 0°C (32°F) or higher for 4 hours or more before performing the troubleshooting.

OPERATION

AWC-ECU controls the electric pump by the information from AWC pressure sensor and electric pump relay.

DTC SET CONDITIONS

The code is set when the electric pump operation signal is output from AWC-ECU, and when the AWC pressure sensor signal is not reached the specified pressure after the specified time has elapsed.

PROBABLE CAUSES

- Fluid malfunction (low fluid level)
- AWC pressure sensor malfunction
- Electric pump relay malfunction
- Hydraulic unit malfunction
- Electric pump malfunction
- Damaged harness wires and connectors
- Malfunction of AWC-ECU
- Used under low temperature condition

DIAGNOSTIC PROCEDURE

STEP 1. Check whether the diagnostic trouble code is reset.

As for vehicles under low temperature condition, carry out the contents of the precautions, and then check the diagnostic trouble code again.

Q. Is DTC No.C161E set?

YES Go to Step 2.
NO This diagnosis is complete.
STEP 2. Scan tool CAN bus diagnostics

Using scan tool MB991958, diagnose the CAN bus lines.

Q. Is the check result normal?

YES Go to Step 4.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart.) After repairing the CAN bus line, go to Step 3.
STEP 3. Check whether the DTC is reset.

Q. Is DTC No. C161E set?

YES Go to Step 4.
NO This diagnosis is complete.
STEP 4. Fluid check

Check that the fluid level is adequate. Active Yaw Control (AYC) Fluid Level Check.)

Q. Is the check result normal?

YES Go to Step 5.
NO Add the fluid. Then go to Step 15.
STEP 5. Scan tool diagnostic trouble code

Check if the AWC diagnostic trouble code No. C1611, C1612, C1625, or C161D is set.(Refer to Super All Wheel Control (S-AWC).)

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 6.
STEP 6. Scan tool actuator test

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


Q. Is the check result normal?

YES Go to Step 14.
NO Go to Step 7.
STEP 7. 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 8.
NO Replace the electric pump relay. (Refer to Service and Repair.) Then go to Step 15.
STEP 8. Electric pump relay connector check: A-26X

Q. Is the check result normal?

YES Go to Step 9.
NO Repair the defective connector. Then go to Step 15.
STEP 9. Check the wiring harness between A-26X electric pump relay connector terminal No. 2 and fusible link (35).

Check the power supply line for short or open circuit.

Q. Is the check result normal?

YES Go to Step 10.
NO Repair the wiring harness. Then go to Step 15.
STEP 10. Electric pump connector check: F-14

Q. Is the check result normal?

YES Go to Step 11.
NO Repair the defective connector. Then go to Step 15.
STEP 11. Check the wiring harness between A-26X electric pump relay connector terminal No. 4 and F-14 electric pump connector terminal No. 2.

Check the power supply line for short or open circuit.

Q. Is the check result normal?

YES Go to Step 12.
NO Check C-21 and D-12 intermediate connectors. When no problem is found, repair the wiring harness. Then go to Step 15.
STEP 12. Check the wiring harness between F-14 electric pump connector terminal No. 1 and body ground.

Check the ground line for open circuit.

Q. Is the check result normal?

YES Go to Step 13.
NO Repair the wiring harness. Then go to Step 15.
STEP 13. Check whether the DTC is reset.

Q. Is DTC No. C161E set?

YES Replace the hydraulic unit. Removal and Replacement.) Then go to Step 14.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
STEP 14. Check whether the DTC is reset.

Q. Is DTC No. C161E set?

YES Replace the AWC-ECU.(Refer to Active Center Differential (ACD).) Then go to Step 15.
NO This diagnosis is complete.
STEP 15. Check whether the DTC is reset.

Q. Is DTC No. C161E set?

YES Return to Step 2.
NO This diagnosis is complete.