STEP 1. Using scan tool MB991958, diagnose the CAN bus line
(1) caution | To 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 (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 CAN bus line found to be normal?
Go to Step 2. Repair the CAN bus line. (Refer to GROUP 54C, Diagnosis ).
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
Is the DTC set?
Go to Step 3. It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
STEP 3. Check ambient air temperature sensor connector A-48 and ETACS-ECU connector C-410 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 4. Check the wiring harness between ambient air temperature sensor connector A-48 (terminals 2 and 1) and ETACS-ECU connector C-410 (terminals 7 and 14).
STEP 5. Check the ambient air temperature sensor.
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Return to Step 1. The procedure is complete.