STEP 1. Check harness connector A-41 at battery current sensor for damage
STEP 2. Check battery current sensor itself
STEP 3. Measure the sensor supply voltage at battery current sensor harness side connector A-41.
(1) Disconnect the connector A-41 and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 1 and ground.- Voltage should be between 4.9 and 5.1 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 4.9 and 5.1 volts?
Go to Step 7. Go to Step 4.
STEP 4. Check harness connector B-27 at ECM for damage.
STEP 5. Check for open circuit and short circuit to ground between battery current sensor connector A-41 (terminal No. 1) and ECM connector B-27 (terminal No. 99).
STEP 6. Using scan tool MB991958, read the diagnostic trouble code (DTC).
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC P1608 set?
Replace the ECM (Refer to, Removal and Installation ). Then go to Step 13. 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 7. Check the continuity at battery current sensor harness side connector A-41.
STEP 8. Check harness connector B-27 at ECM for damage.
STEP 9. Check for open circuit and harness damage between battery current sensor connector A-41 (terminal No. 3) and ECM connector B-27 (terminal No. 101).
STEP 10. Check harness connector B-27 at ECM for damage.
STEP 11. Check for harness damage between battery current sensor connector A-41 (terminal No. 1) and ECM connector B-27 (terminal No. 99).
STEP 12. Check for open circuit, short circuit to ground and harness damage between battery current sensor connector A-41 (terminal No. 4) and ECM connector B-27 (terminal No. 100).
STEP 13. Using scan tool MB991958, read the diagnostic trouble code (DTC).
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC P1608 set?
Retry the troubleshooting. The inspection is complete.