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DTC No.C1078: Tire Revolutions Range
 
 
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.
  • Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
AWD-ECU receives the wheel speed data from ASC-ECU via the CAN communication.
 
 
DTC SET CONDITION
This DTC is set when the abnormality below is detected:
  • Difference in rotation speed between the front and rear wheels exceeds continuously a specific value.
 
 
TROUBLESHOOTING HINTS
  • Tire with incorrect diameter equipped
  • Spare tire installed
  • Improper tire pressure
  • Malfunction of ASC-ECU
  • Malfunction of AWD-ECU

 
 
DIAGNOSIS
STEP 1. Scan tool (M.U.T.-III) CAN bus diagnostics.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). After repairing the CAN bus line, go to Step 2.
 
STEP 2. Check whether the DTC is set again.
Is DTC No.C1078 set?
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 - Troubleshooting ).
Is the DTC set?
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 AWD-ECU. (Refer to ).