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Inspection Procedure 3

INSPECTION PROCEDURE 3
The Check Engine/Malfunction Indicator Lamp Does Not Illuminate Right after the Ignition Switch Is Turned to the "ON" Position.




WIRING DIAGRAM and CONNECTOR VIEW




CIRCUIT OPERATION
- The check engine/malfunction indicator lamp power is supplied from the ignition switch.
- The ECM controls the ground of the check engine/malfunction indicator lamp by turning the power transistor in the ECM "ON" and "OFF."

COMMENT
- The ECM causes the check engine/malfunction indicator lamp to illuminate for 5 seconds immediately after the ignition switch is turned to "ON" occurred.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Burnt-out bulb.
- Detective check engine/malfunction indicator lamp circuit.
- Malfunction of the ECM.

DIAGNOSIS

Required Special Tool:
MB991502: Scan Tool




STEP 1. Using scan tool MB991502, check data list item 16: Power Supply Voltage.

CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.

- Voltage should be approximately 12 volts (battery positive voltage).
If within specifications, go to Step 2.
If not within specifications, refer to INSPECTION PROCEDURE 26 - Power Supply and Ignition Switch - IG System.




STEP 2. Check the circuit at the ECM connector C-53.
(1) Disconnect connector C-53 and measure at the harness side.
(2) Turn the ignition switch "ON."
(3) Using a jumper wire, ground terminal 36 to the ground.
- The check engine/malfunction indicator lamp should illuminate.
(4) Turn the ignition switch "OFF."
If the lamp does not illuminate, go to Step 3.
If the lamp illuminate, go to Step 6.

STEP 3. Check the burnt-out bulb.
If burnt out, go to Step 4.
If not burnt out, replace the bulb. Then confirm that the malfunction symptom is eliminated.




STEP 4. Check the circuit at the combination meter connector C-04.
(1) Disconnect connector C-04 and measure at the harness side.
(2) Turn the ignition switch "ON."
(3) Connect terminal 24 and the ground via a 20-ohms resistor. Measure the current at this time.
- The current should be 0.5 ampere or more.
(4) Turn the ignition switch "OFF."
If within specifications, go to Step 5.
If not within specifications, check the harness wire and connector between the combination meter and the ignition switch and repair or replace. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.

STEP 5. Check the harness wire between the combination meter connector C-04 and the ECM connector C-53.

NOTE: After inspecting the intermediate connector C-16, inspect the wire. if the intermediate connector C-16 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.

If the wire between the combination meter connector C-04 and the ECM connector C-53 is damaged, repair it.
If the wire between the combination meter connector C-04 and the ECM connector C-53 is damaged, repair or replace the combination meter connector C-04. Refer to Harness Connector Inspection.
Then confirm that the malfunction symptom is eliminated.

STEP 6. Check harness connector C-53 at the ECM for damage.
If harness connector C-53 is damaged, repair or replace it. Refer to Harness Connector Inspection.
If harness connector C-53 is in good condition, replace the ECM.
Then confirm that the malfunction symptom is eliminated.
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