[Previous][Next]
DTC U15A3 Odometer information lost
 
 
caution
  • If the DTC U15A3 set in the occupant classification-ECU, always diagnose the CAN main bus lines.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
TROUBLE JUDGMENT
If the signal from combination meter cannot be received, the occupant classification-ECU sets DTC U15A3.
 
 
JUDGMENT CRITERIA
Because of the CAN-C bus circuit malfunction, if occupant classification-ECU becomes unable to perform the normal data transmission, occupant classification-ECU determines that an abnormality is present.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective
  • The combination meter may be defective
  • The occupant classification-ECU may be defective
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the scan tool ."
(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 CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool MB991958, read the combination meter diagnostic trouble code
Check if DTC is set in the combination meter.
Is the DTC set?
Diagnose the combination meter. Then go to Step 4.
Go to Step 3.
 
STEP 3. Using scan tool MB991958, read diagnostic trouble code No. U1108 for other system.
Check if DTC U1108 is set in ETACS-ECU, SRS-ECU, ASC-ECU.
Is the DTC set?
Replace the combination meter (Refer to GROUP 54A, Combination Meter ).
Go to Step 4.
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the occupant classification-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Replace the front seat cushion cover and pad assembly (Refer to GROUP 52A, Front Seat Assembly ).
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).