C1612

DTC C1612: AWC Pressure Sensor System (High Voltage)





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 the electric pump by the information from AWC pressure sensor.

DTC SET CONDITIONS
The code is set when AWC pressure sensor output voltage is 4.6 V or more.

PROBABLE CAUSES
^ AWC pressure sensor 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. After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.

Q: Is DTC No. C1612 set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Scan tool diagnostic trouble code
Check if the ACD-related DTC No.C1625 is set.

Q: Is the DTC set?
YES: Perform the relevant troubleshooting. Then go to Step 9.
NO: Go to Step 4.

STEP 4. AWC-ECU connector, intermediate connector, AWC pressure sensor connector check: C-51, D-11, F-27

Q: Is the check result normal?
YES: Go to Step 5.
NO: Repair the defective connector. Then go to Step 9.

STEP 5. Check the wiring harness between C-51 AWC-ECU connector terminal No.7 and F-27 AWC pressure sensor connector terminal No.2.
Check the output line for short (for short to the power supply) or open circuit.

Q: Is the check result normal?
YES: Go to Step 6.
NO: Repair the wiring harness. Then go to Step 9.

STEP 6. Check the wiring harness between C-51 AWC-ECU connector terminal No.8 and F-27 AWC pressure sensor connector terminal No.3.
Check the ground line for open circuit.

Q: Is the check result normal?
YES: Go to Step 7.
NO: Check D-11 intermediate connector. When no problem is found, repair the wiring harness. Then go to Step 9.

STEP 7. Scan tool data list
Item No.87: Pressure sensor output voltage.

Q: Is the check result normal?
YES: Go to Step 8.
NO: Replace the hydraulic unit. Then go to Step 8.

STEP 8. Check whether the DTC is reset.

Q: Is DTC No. C1612 set?
YES: Replace the AWC-ECU. Then go to Step 9.
NO: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction).

STEP 9. Check whether the DTC is reset.

Q: Is DTC No. C1612 set?
YES: Return to Step 1.
NO: This diagnosis is complete.