ABS
DTC C2116: Abnormality in power supply voltage in pump motor
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.
CIRCUIT OPERATION
^ ABS-ECU contains the power supply circuit (terminal No.13) for the pump motor. The pump motor is energized by the motor switch, which is incorporated in ABS-ECU.
^ The pump motor switch, which is incorporated in ABS-ECU, is always off unless the ABS is operating or motor or solenoid valve check is activated when the vehicle is started.
^ ABS-ECU activates the pump motor by turning on the ECU built-in pump motor switch.
DTC SET CONDITIONS
This diagnostic trouble codes will be set under the cases below:
^ When the power supply voltage of the pump motor, which is not in operation, is abnormally low for a prolonged period
^ When the power supply voltage of the pump motor, which is not in operation, is abnormally high for a prolonged period
PROBABLE CAUSES
Current trouble
^ Fusible link malfunction
^ Damaged wiring harness and connectors
^ Abnormality in battery or generator
^ ABS-ECU malfunction
Past trouble
^ Carry out diagnosis with particular emphasis on wiring harness and connector failures between the power supply circuit (A-01 ABS-ECU connector terminal No. 13) to the ABS-ECU motor and the ground circuit (A-01 ABS-ECU connector terminal No. 14). For diagnosis procedures, refer to How to treat past trouble.
DIAGNOSIS
Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness
^ MB991974: ABS check harness
STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 3.
NO: Repair the CAN bus lines. On completion, go to Step 2.
STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines
Q: Is DTC C2116 set?
YES: Go to Step 3.
NO: The procedure is complete.
STEP 3. Fusible link check: Check the fusible link No.26.
Q: Is the check result normal?
YES: Go to Step 4.
NO: Replace the fusible link No.26.
STEP 4. Battery check
Refer to Battery Test.
Q: Is the battery in good condition?
YES: Go to Step 5.
NO: Charge or replace the battery.
STEP 5. Charging system check
Refer to Output Current Test.
Q: Is the charging system in good condition?
YES: Go to Step 6.
NO: Repair or replace the charging system component(s).
STEP 6. Voltage measurement at the A-01 ABS-ECU connector
1) Disconnect the connector, connect special tool MB991974 to the harness-side connector, and measure the voltage at the special tool connector side.
NOTE: Do not connect the special tool MB991974 to ABS-ECU.
2) Turn the ignition switch to the ON position.
3) Measure the voltage between the terminal No. 13 and the body ground.
OK: Approximately battery voltage
Q: Is the check result normal?
YES: Go to Step
8.
NO: Go to Step 7.
STEP 7. Connector check: A-01 ABS-ECU connector
Q: Is the check result normal?
YES: The open or short circuit may be present in the solenoid valve power supply circuit. Repair the wiring harness between the A-01 ABS-ECU connector terminal No.13 and the fusible link No.26.
NO: Repair the defective connector.
STEP 8. Resistance measurement at A-01 ABS-ECU connector
1) Disconnect the connector, connect special tool MB991974 to the harness-side connector, and measure the voltage at the special tool connector side.
NOTE: Do not connect the special tool MB991974 to ABS-ECU.
2) Resistance between terminal No.1 and body ground, and between terminal No.14 and body ground.
OK: Continuity exists (2 ohms or less)
Q: Is the check result normal?
YES: Go to Step 10.
NO: Go to Step 9.
STEP 9. Connector check: A-01 ABS-ECU connector
Q: Is the check result normal?
YES: An open circuit may be present in the ground circuit. Repair the wiring harness between the A-01 ABS-ECU terminal No.1 and body ground, and between the A-01 ABS-ECU terminal No.14 and body ground.
NO: Repair the defective connector.
STEP 10. Check whether the diagnostic trouble code is reset.
1) Erase the diagnostic trouble code.
2) Drive the vehicle at 12 mph (20 km/h) or more.
NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12 mph (20 km/h) or higher.
Q: Is DTC C2116 set?
YES: Replace the ABS-ECU.
NO: Intermittent malfunction.