23A-DTC C1078 TIRE TURNING MALFUNCTION

DTC C1078: Tire Revolutions Range

caution

If there is any problem in the CAN bus lines, an incorrect DTC may be stored. 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 receives the wheel speed data from ASC-ECU via the CAN communication.

DTC SET CONDITION

This DTC is stored when the abnormality below is detected:

Difference in rotation speed between the front and rear wheels exceeds continuously a specific value.

PROBABLE CAUSES

Tire with incorrect diameter equipped
Spare tire installed
Improper tire pressure
Malfunction of ASC-ECU
Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics.

Use scan tool (M.U.T.-III) to perform the CAN bus diagnosis.

Is the check result normal?

Go to Step 3

Repair the CAN bus line (Refer to GROUP 54C - Diagnosis, Can Bus Diagnostics Table

). After repairing the CAN bus line, go to Step 2

STEP 2. Check whether the DTC is stored again.

Is DTC No.C1078 stored?

Go to Step 3

This diagnosis is complete.

STEP 3. Check the tires

Check that the wheels/tires with the identical size are installed, and that each tire pressure is within the value specified on the tire pressure label.

Is the check result normal?

Go to Step 4

Install the wheels/tires with the identical size, or adjust the tire pressure. Then go to Step 5

STEP 4. Scan tool (M.U.T.-III) other system DTC.

Check the ASC DTC (Refer to GROUP 35C - Diagnosis, Diagnostic Trouble Code Chart

Is the DTC stored?

Perform the relevant troubleshooting.

Go to Step 5

STEP 5. Scan tool (M.U.T.-III) data list.

Check the following data list. (Refer to

Item No.18: FL wheel speed sensor
Item No.19: FR wheel speed sensor
Item No.20: RL wheel speed sensor
Item No.21: RR wheel speed sensor

Is the check result normal?

Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

Replace the AWC-ECU. (Refer to