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DTC C161E: Electric Pump System


AWC PUMP RELAY SYSTEM CIRCUIT


Refer to .
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 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



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 diagnostic trouble code No.C161E set?
Go to Step 2.
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?
Go to Step 4.
Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting ). After repairing the CAN bus line, go to Step 3.

STEP 3. Check whether the DTC is reset.

Q. Is DTC No. C161E set?
Go to Step 4.
This diagnosis is complete.

STEP 4. Fluid check
Check that the fluid level is adequate. (Refer to ).

Q. Is the check result normal?
Go to Step 5.
Add the fluid.

STEP 5. Scan tool diagnostic trouble code
Check if the ACD diagnostic trouble code No.C1611, C1612, C1625, or C161D is set. (Refer to ).

Q. Is the DTC set?
Perform the relevant troubleshooting.
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?
Go to Step 14.
Go to Step 7.

STEP 7. Electric pump relay check.
Check the electric pump relay. (Refer to ).

Q. Is the check result normal?
Go to Step 8.
Replace the electric pump relay. (Refer to ). Then go to Step 15.

STEP 8. Electric pump relay connector check: A-22X

Q. Is the check result normal?
Go to Step 9.
Repair the defective connector. Then go to Step 15.

STEP 9. Check the wiring harness between A-22X 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?
Go to Step 10.
Repair the wiring harness. Then go to Step 15.

STEP 10. Electric pump connector check: F-29

Q. Is the check result normal?
Go to Step 11.
Repair the defective connector. Then go to Step 15.

STEP 11. Check the wiring harness between A-22X electric pump relay connector terminal No.4 and F-29 electric pump connector terminal No.2.
Check the power supply line for short or open circuit.

Q. Is the check result normal?
Go to Step 12.
Check C-136 and D-13 intermediate connectors. When no problem is found, repair the wiring harness. Then go to Step 15.

STEP 12. Check the wiring harness between F-29 electric pump connector terminal No.1 and body ground.
Check the ground line for open circuit.

Q. Is the check result normal?
Go to Step 13.
Repair the wiring harness. Then go to Step 15.

STEP 13. Check whether the DTC is reset.

Q. Is DTC No. C161E set?
Replace the hydraulic unit. (Refer to ). Then go to Step 14.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 14. Check whether the DTC is reset.

Q. Is DTC No. C161E set?
Replace the AWC-ECU. (Refer to ). Then go to Step 15.
This diagnosis is complete.

STEP 15. Check whether the DTC is reset.

Q. Is DTC No. C161E set?
Return to Step 2.
This diagnosis is complete.