STEP 1. Check gateway-ECU connector C-49 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 2. Measure the voltage at gateway-ECU connector C-49.
(1) Disconnect the gateway-ECU connector C-49, and measure at the wiring harness side.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Measure the voltage between the gateway-ECU connector C-49 terminal No. 13 and the body ground.- The voltage should measure approximately 12 volts (battery positive voltage).
Is the measured voltage approximately 12 volts (battery positive voltage)?
Go to Step 4. Go to Step 3.
STEP 3. Check the wiring harness between the battery (fusible link No. 36) and gateway-ECU connector C-49 terminal No. 13.
STEP 4. Measure the voltage at gateway-ECU connector C-49.
(1) Disconnect the gateway-ECU connector C-49, and measure at the wiring harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between the gateway-ECU connector C-49 terminal No. 12 and the body ground.- The voltage should measure approximately 12 volts (battery positive voltage).
Is the measured voltage approximately 12 volts (battery positive voltage)?
Go to Step 7. Go to Step 5.
STEP 5. Using scan tool MB991958, check other system data list.
STEP 6. Check the wiring harness between the IG1 relay and gateway-ECU connector C-49 terminal No. 12.
STEP 7. Measure the resistance at gateway-ECU connector C-49.
STEP 8. Check the wiring harness between the gateway-ECU connector C-49 terminal No. 14 and body ground.
STEP 9. Retest the system.