INSPECTION PROCEDURE 2: When the Ignition Key is Turned to "ON" (Engine Stopped), the ABS Warning Lamp does not Illuminate.

CIRCUIT OPERATION

The ABS warning lamp is lit up by transistor control in the ABS-ECU. However, the relationship of the reverse circuit movement in the combination meter will vary from usual in terms of transistor ON/OFF and ABS warning lamp ON/OFF, in that the ABS warning lamp will light up when the transistor is turned OFF for this circuit. This is how the ABS warning lamp lights up even when the ABS-ECU connector is connected improperly or if the ABS-ECU function has terminated.

The ABS-ECU also lights up the ABS warning lamp during the initial check (approximately 3 seconds) when the ignition switch is turned ON in addition to when the system is malfunctioning.

TECHNICAL DESCRIPTION (COMMENT)

Possible causes include the combination meter power circuit, disconnected earth circuit, dead lamp bulb, or short circuited ABS warning lamp.

TROUBLESHOOTING HINTS (The most likely causes for this case:)

Blown fuse

Damaged wiring harness or connector

Burnt out ABS warning lamp bulb

Combination meter defect

Malfunction of the hydraulic unit (integrated with ABS-ECU)

DIAGNOSIS

STEP 1. Check the ABS warning lamp circuit at ABS-ECU connector B-03.

Disconnect ABS-ECU connector B-03.

Turn the ignition switch to the "ON" position.

Q: Does the ABS warning lamp illuminate?

YES: To check and reproduce the state of malfunction replace the hydraulic unit (integrated with ABS-ECU). Then go to Step 7

. If the malfunction is not reproduced, an intermittent malfunction is suspected. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

.
NO: Go to Step 2

STEP 2. Check the ABS warning lamp bulb.

Remove the combination meter (Refer to GROUP 54A, Combination Meter ).

Check the ABS warning lamp bulb.

Q: Is the bulb burned out?

YES: Replace the bulb and then go to Step 7

.
NO: Go to Step 3

STEP 3. Measure the voltage at the combination meter connector C-04.

Disconnect connector C-04, and check at the harness side.

Turn the ignition switch to the "ON" position.

Measure the voltage between terminal 42 and earth.

OK: System voltage

Q: Is the check result normal?

YES: Go to Step 4

.
NO: Go to Step 6

STEP 4. Check the harness wire between the combination meter connector C-05 terminal 12 and earth.

Q: Is the harness wire between combination meter connector C-05 terminal 12 and earth?

YES: Go to Step 5

.
NO: Repair it and go to Step 7

STEP 5. Check the harness wire between the combination meter connector C-05 terminal 18 and ABS-ECU connector B-03 terminal 12.

NOTE: After inspecting intermediate connector C-105, inspect the wire. If the intermediate connector C-105 is damaged, repair or replace it. Then go to Step 7

Q: Is the harness wire between the combination meter connector C-05 terminal 18 and ABS-ECU connector B-03 terminal 12 damaged?

YES: Replace the combination meter and go to Step 7

.
NO: Repair it and go to Step 7

STEP 6. Check the harness wire between the ignition switch (IG1) C-303 terminal 2 and the combination meter C-04 terminal 42.

NOTE: After inspecting intermediate connectors C-203 and C-205, inspect the wire. If the intermediate connector C-203 or C-205 is damaged, repair or replace it. Then go to Step 7

Q: Is the harness wire between the ignition switch (IG1) C-303 terminal 2 and combination meter connector C-04 terminal 42 earth?

YES: Repair it and go to Step 7

.
NO: Go to Step 7

STEP 7. Retest the system.

Q: Does the ABS warning lamp 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


INSPECTION PROCEDURE 2: When the Ignition Key is Turned to "ON" (Engine Stopped), the ABS Warning Lamp does not Illuminate.

CIRCUIT OPERATION The ABS warning lamp is lit up by transistor control in the ABS-ECU. However, the relationship of the reverse circuit movement in the combination meter will vary from usual in terms of transistor ON/OFF and ABS warning lamp ON/OFF, in that the ABS warning lamp will light up when the transistor is turned OFF for this circuit. This is how the ABS warning lamp lights up even when the ABS-ECU connector is connected improperly or if the ABS-ECU function has terminated. The ABS-ECU also lights up the ABS warning lamp during the initial check (approximately 3 seconds) when the ignition switch is turned ON in addition to when the system is malfunctioning.
TECHNICAL DESCRIPTION (COMMENT) Possible causes include the combination meter power circuit, disconnected earth circuit, dead lamp bulb, or short circuited ABS warning lamp.
TROUBLESHOOTING HINTS (The most likely causes for this case:) Blown fuse Damaged wiring harness or connector Burnt out ABS warning lamp bulb Combination meter defect Malfunction of the hydraulic unit (integrated with ABS-ECU)
	DIAGNOSIS

	STEP 1. Check the ABS warning lamp circuit at ABS-ECU connector B-03. Disconnect ABS-ECU connector B-03. Turn the ignition switch to the "ON" position. Q: Does the ABS warning lamp illuminate? YES: To check and reproduce the state of malfunction replace the hydraulic unit (integrated with ABS-ECU). Then go to Step 7 . If the malfunction is not reproduced, an intermittent malfunction is suspected. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction. NO: Go to Step 2.
	STEP 2. Check the ABS warning lamp bulb. Remove the combination meter (Refer to GROUP 54A, Combination Meter ). Check the ABS warning lamp bulb. Q: Is the bulb burned out? YES: Replace the bulb and then go to Step 7. NO: Go to Step 3.
	STEP 3. Measure the voltage at the combination meter connector C-04. Disconnect connector C-04, and check at the harness side. Turn the ignition switch to the "ON" position. Measure the voltage between terminal 42 and earth. OK: System voltage Q: Is the check result normal? YES: Go to Step 4 . NO: Go to Step 6.
	STEP 4. Check the harness wire between the combination meter connector C-05 terminal 12 and earth. Q: Is the harness wire between combination meter connector C-05 terminal 12 and earth? YES: Go to Step 5 . NO: Repair it and go to Step 7.
	STEP 5. Check the harness wire between the combination meter connector C-05 terminal 18 and ABS-ECU connector B-03 terminal 12. NOTE: After inspecting intermediate connector C-105, inspect the wire. If the intermediate connector C-105 is damaged, repair or replace it. Then go to Step 7 . Q: Is the harness wire between the combination meter connector C-05 terminal 18 and ABS-ECU connector B-03 terminal 12 damaged? YES: Replace the combination meter and go to Step 7. NO: Repair it and go to Step 7.
	STEP 6. Check the harness wire between the ignition switch (IG1) C-303 terminal 2 and the combination meter C-04 terminal 42. NOTE: After inspecting intermediate connectors C-203 and C-205, inspect the wire. If the intermediate connector C-203 or C-205 is damaged, repair or replace it. Then go to Step 7 . Q: Is the harness wire between the ignition switch (IG1) C-303 terminal 2 and combination meter connector C-04 terminal 42 earth? YES: Repair it and go to Step 7. NO: Go to Step 7.
	STEP 7. Retest the system. Q: Does the ABS warning lamp 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 .