Active Center Differential (ACD)

DTC C2100: Battery Voltage Malfunction (Low Voltage)

Power supply system circuit





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 power supply is provided from the battery via ETACS-ECU.

DTC SET CONDITIONS
This diagnostic trouble code is set when the abnormality below is detected: When the AWC-ECU power supply voltage and solenoid valve power supply voltage are 9 V or less.

PROBABLE CAUSES
^ Malfunction of the ETACS-ECU
^ Defective battery
^ Charging system failed
^ 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. C21 00 set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Scan tool diagnostic trouble code
Check the ETACS diagnostic trouble code.

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

STEP 4. Check the battery.

Q: Is the check result normal?
YES: Go to Step 6.
NO: Charge or replace the battery. Then go to Step 5.

STEP 5. Check the charging system.

Q: Is the check result normal?
YES: Go to Step 6.
NO: Repair or replace the charging system component(s).

STEP 6. Voltage measurement at C-51 AWC-ECU connector
Disconnect the connector, and measure the voltage between terminal No. 12 and ground at the wiring harness side.
OK: Battery positive voltage

Q: Is the check result normal?
YES: Go to Step 10.
NO: Go to Step 7.

STEP 7. AWC-ECU connector, ETACS-ECU connector check: C-51, C-315

Q: Is the check result normal?
YES: Go to Step 8.
NO: Repair the defective connector. Then go to Step 13.

STEP 8. Check the wiring harness between C-51 AWC-ECU connector terminal No. 12 and C-315 ETACS-ECU connector terminal No.4.
Check the power supply line for short or open circuit.

Q: Is the check result normal?
YES: Go to Step 9.
NO: Check C-35 intermediate connector. When no problem is found, repair the wiring harness. Then go to Step 13.

STEP 9. Scan tool data list
Item No.43: Battery voltage.

Q: Is the check result normal?
YES: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction).
NO: Replace the ETACS-ECU. Then go to Step 13.

STEP 10. AWC-ECU connector check: C-51

Q: Is the check result normal?
YES: Go to Step 11.
NO: Repair the defective connector. Then go to Step 13.

STEP 11. Check the wiring harness between C-51 AWC-ECU connector terminal No.13 and body ground.
Check the ground line for open circuit.

Q: Is the check result normal?
YES: Go to Step 12.
NO: Repair the wiring harness. Then go to Step 13.

STEP 12. Scan tool data list
Item No.43: Battery voltage.

Q: Is the check result normal?
YES: Intermittent malfunction. (Refer to How to Cope with Intermittent Malfunction).
NO: Replace the AWC-ECU. Then go to Step 13.

STEP 13. Check whether the DTC is reset.

Q: Is DTC No. C2100 set?
YES: Return to Step 1.
NO: This diagnosis is complete.