Inspection Procedure 3

Part 1 Of 2:

Part 2 Of 2:

INSPECTION PROCEDURE 3: When the Ignition Switch is Turned to the "ON" (Engine Stopped or After Start-up), the TCL Warning Light does not Illuminate.

CIRCUIT OPERATION
^ Power to the TCL warning light is supplied from the ignition switch. The ABS-ECU grounds the circuit to illuminate the light.
^ The ABS-ECU illuminates the TCL warning light for 3 seconds while running self-check. This light should be illuminated for 3 seconds after the ignition switch is turned on (with the engine stopped).

TECHNICAL DESCRIPTION (COMMENT)
The cause may be: an open circuit in the TCL warning light power supply circuit, a blown TCL warning light bulb or ABS-ECU.

TROUBLESHOOTING HINTS
^ Blown fuse
^ Damaged wiring harness or connector
^ Burnt out TCL warning light bulb
^ Malfunction of the ABS-ECU

DIAGNOSIS

Required Special Tool:
^ MB991223: Harness Set

STEP 1. Check the power supply circuit at ABS-ECU connector A-03.
1. Disconnect connector A-03 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.





3. The TCL warning light should illuminate when terminal 15 is grounded.
Q: Does the TCL warning light illuminate?
YES: Replace the hydraulic unit (integrated with ABS-ECU) and then go to Step 7.
NO: Go to Step 2.

STEP 2. Check the TCL warning light bulb.
1. Remove the combination meter.
2. Check the TCL warning light bulb.
Q: Is the TCL warning light bulb burned out?
YES: Replace the bulb and then go to Step 7.
NO: Go to Step 3.

STEP 3. Check the combination meter for the continuity.





1. Remove the combination meter.
2. Remove the TCL warning light bulb. Then measure the resistance between the bulb terminals.
3. Install the TCL warning light bulb to the combination meter, and then measure the resistance between connector C-29 terminals 29 and 31. The resistance reading at this time should be much the same as the resistance measured at step (2).
Q: Are the two resistance values extremely different each other?
YES: Replace the combination meter (printed circuit board).
NO: (much the same): Go to Step 4.

STEP 4. Check the power supply circuit at the combination meter.
1. Disconnect connector C-29, and check at the harness side.
2. Turn the ignition switch to the "ON" position.





3. Measure the voltage between terminal 29 and ground. It should be battery positive voltage (approximately 12 volts).
Q: Is battery positive voltage (approximately 12 volts) present?
YES: Go to Step 5.
NO: Go to Step 6.

STEP 5. Check the harness wire between the combination meter connector C-29 terminal 31 and the ABS-ECU connector A-03 terminal 15.











NOTE: After inspecting intermediate connector C-12, inspect the wire. If intermediate connector C-12 is damaged, repair or replace it. If the connector has been repaired or replaced, go to Step 7.

Q: Is any harness wire between the combination meter connector C-29 terminal 31 and the ABS-ECU connector A-03 terminal 15 in good condition?
YES: Go to Step 7.
NO: Repair the harness wire and then go to Step 7.

STEP 6. Check the harness wire between the ignition switch (IG1) connector C-58 terminal 2 and the combination meter connector C-29 terminal 29.











NOTE: After inspecting intermediate connectors C-87 and C-84, inspect the wires. If intermediate connector C-87 or C-84 is damaged, repair or replace it. If the connector has been repaired or replaced, go to Step 7.

Q: Is any harness wire between the ignition switch (IG1) connector C-58 terminal 2 and the combination meter connector C-29 terminal 29 in good condition?
YES: Go to Step 7.
NO: Repair the harness wire and then go to Step 7.

STEP 7. Retest the system.
Q: Does the TCL warning light illuminate for 3 seconds when the ignition switch is turned to the "ON" position with engine stopped or upon start-up?
YES: The procedure is complete.
NO: Return to Step 1.