Code No.C1215: Rear left wheel speed sensor (open circuit/short to earth/short to power supply)




OPERATION


The wheel speed sensor is a pulse generator. It consists of encoder (a plate on which north and south pole sides of the magnets are arranged alternately) for detecting wheel speed which rotates at the same speed as the road wheels. This sensor outputs frequency pulse signals in proportion to wheel speed.
The pulse signals, which the wheel speed sensor creates, are sent to the ABS-ECU. The ABS-ECU uses the frequency of the pulse signals to determine the wheel speed.

DIAGNOSIS CODE SET CONDITIONS


The ABS-ECU monitors the voltage change in each of the wheel speed sensor circuits. If the ECU detects an open or short circuit in any of the circuits, the ECU sets the diagnosis code.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-15 rear left wheel speed sensor connector


Q. Is the check result normal?

Go to Step 2.

Repair the defective connector.

STEP 2. Remove the rear left wheel speed sensor and check it.
Refer to .

Q. Is the check result normal?
Go to Step 3.
Replace the rear left wheel speed sensor (Refer to ).

STEP 3. Check the ABS-ECU connector A-05.

Check the connectors, for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is the check result normal?

Go to Step 4.

Repair or replace the damaged component(s).

STEP 4. Check the continuity (short to earth) at ABS-ECU connector A-05.



(1)Disconnect the rear left wheel speed sensor connector C-15 and ABS-ECU connector A-05, and connect special tool ABS Check Harness (MB991951) to the wiring harness-side connector.
note Do not connect special tool ABS Check Harness (MB991951) to the ABS-ECU.
(2)Continuity between ABS-ECU connector A-05 terminal 21 and body earth
OK: No continuity
(3)Continuity between ABS-ECU connector A-05 terminal 10 and body earth
OK: No continuity

Q. Is the check result normal?

Go to Step 5.

Repair the wiring harness between ABS-ECU connector A-05 and rear left wheel speed sensor connector C-15.

STEP 5. Measure the resistance at ABS-ECU connector A-05.



(1)Disconnect the rear left wheel speed sensor connector C-15 and ABS-ECU connector A-05, and connect special tool ABS Check Harness (MB991951) to the wiring harness-side connector.
note Do not connect special tool ABS Check Harness (MB991951) to the ABS-ECU.

(2)Resistance between ABS-ECU connector A-05 terminal 21 and rear left wheel speed sensor C-15 terminal 1
OK: 10 Ω or less
(3)Resistance between ABS-ECU connector A-05 terminal 10 and rear left wheel speed sensor C-15 terminal 2
OK: 10 Ω or less

Q. Is the check result normal?

Go to Step 6.

Repair the wiring harness between ABS-ECU connector A-05 and rear left wheel speed sensor connector C-15.

STEP 6. Check whether the diagnosis code is reset.

caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.
(7)Disconnect M.U.T.-III.

Q. Is code No.C1215 set?

Replace the hydraulic unit (integrated with ABS-ECU) (Refer to ).

The malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .