FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Mitsubishi >> 2011 >> Lancer Sportback L4-2.0L Turbo (4B11T) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> C Code Charts >> C100A >> Active Stability Control System (ASC)

Active Stability Control System (ASC)




DTC C100A Abnormality in FL wheel speed sensor circuit













CAUTION:

- If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines CAN Bus Line Diagnostics Flow.
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
- When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor, the G and yaw rate sensor and brake fluid pressure sensor (Refer to Active Stability Control System (ASC) , Active Stability Control System (ASC) and Active Stability Control System (ASC).

OPERATION

- Each wheel speed detecting section is a kind of a pulse generator. It consists of the encoder (plate on which the north and south pole of magnet are arranged alternately) for detecting the wheel speed, which rotates at the same speed of the wheels, and the wheel speed sensor. This detecting section outputs the frequency pulse signals in proportion to the wheel speed.
- The pulse signals generated by the wheel speed detecting section are sent to ASC-ECU. ASC-ECU uses the frequency of the pulse signals to determine the wheel speed.

DTC SET CONDITIONS

ASC-ECU monitors the voltage fluctuation in each wheel speed sensor circuit. If ASC-ECU detects the open or short circuit in the circuit, it will set a DTC.

PROBABLE CAUSES

Current trouble

- Damaged wiring harness and connectors
- Noise interference
- Malfunction of wheel speed sensor
- Malfunction of ASC-ECU

Past trouble

- Carry out diagnosis with particular emphasis on wiring harness and connector failures between ASC-ECU and the wheel speed sensor. For diagnosis procedures, refer to How to treat past trouble (How to Use Troubleshooting/How to Treat Past Trouble 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 A
- MB991997: ASC check harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.

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 CAN Bus Diagnostics Chart).
On completion, go to Step 2.
STEP 2. DTC recheck after resetting CAN bus lines

Q. Is DTC C100A set?

YES Go to Step 3.
NO The procedure is complete.
STEP 3. Using scan tool MB991958, check the data list

Check the following data list (Refer to Data List Reference Table).

- Item No.01: FL wheel speed sensor

Q. Is the check result normal?

YES Go to Step 10.
NO Go to Step 4.
STEP 4. Connector check: A-51 ASC-ECU connector, A-07 front wheel speed sensor [LH] connector

Q. Is the check result normal?

YES Go to Step 5.
NO Repair the defective connector. Then go to Step 11.
STEP 5. Voltage measurement at the A-51 ASC-ECU connector





(1)Disconnect the ASC-ECU connector, connect special tool ASC check harness (MB991997) to the harness-side connector, and then measure the voltage at the special tool connector side.
NOTE:
Do not connect the special tool to ASC-ECU.

(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between the front wheel speed sensor (LH) power supply terminal
(signal terminal) No.45 and the body ground and between the ground terminal No.46 and the body ground.
OK: 1 volt or less
Q. Is the check result normal?

YES Go to Step 6.

NO (Not normal at the terminal No.45 or No.46) : Go to Step 8.

STEP 6. Resistance measurement at A-51 ASC-ECU connector





(1)Disconnect the ASC-ECU connector, connect special tool ASC check harness (MB991997) to the harness-side connector, and then measure the resistance at the special tool connector side.
NOTE:
Do not connect the special tool to ASC-ECU.

(2)Measure the resistance between the front wheel speed sensor (LH) power supply terminal
(signal terminal) No.45 and the body ground and between the front wheel speed sensor (LH) ground terminal No.46 and the body ground.
OK: No continuity
Q. Is the check result normal?

YES Go to Step 7.

NO (Not normal at the terminal No.45 or No.46) : Go to Step 8.

STEP 7. Voltage measurement at the A-51 ASC-ECU connector





(1)Disconnect the ASC-ECU connector, connect special tool ASC check harness (MB991997) to the ASC-ECU-side connector and harness-side connector, and then measure the voltage at the special tool connector side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between the front wheel speed sensor (LH) power supply terminal
(signal terminal) No.45 and body ground, and between the ground terminal No.46 and body ground.
OK:

Terminal No.45 and body ground: Battery positive voltage
Terminal No.46 and body ground: 1 volt or less

Q. Is the check result normal?

YES Go to Step 8.

NO Go to Step 10.

STEP 8. Check for wheel speed sensor [FL] as a single unit

Refer to Wheel Speed Sensor Inspection.

Q. Is the check result normal?

YES Go to Step 9.
NO Replace the wheel speed sensor [FL] (Refer to Active Stability Control System (ASC)). Then go to Step 11.
STEP 9. Wiring harness check between A-51 ASC-ECU connector terminal No.45 and A-07 front wheel speed sensor [LH] connector terminal No.1 and between A-51 ASC-ECU connector terminal No.46 and A-07 front wheel speed sensor [LH] connector terminal No.2.

- Check for open or short circuit in front wheel speed sensor[ LH] circuit.

Q. Is the check result normal?

YES Go to Step 10.
NO Repair the wiring harness. Then go to Step 11.
STEP 10. Check whether the DTC is reset.

(1)Erase the DTC.

(2)Drive the vehicle at 12 mph (20 km/h) or higher.
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 C100A set?

YES Replace the hydraulic unit (integrated with ASC-ECU) (Refer to Active Stability Control System (ASC)). Then go to Step 11.
NO Intermittent malfunction How to Cope With Intermittent Malfunctions).
STEP 11. Check whether the DTC is reset.

(1)Erase the DTC.

(2)Drive the vehicle at 12 mph (20 km/h) or higher.
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 C100A set?

YES Return to Step 1.
NO The procedure is complete.
pro multis Credits:Operation CHARM About Operation CHARM