INSPECTION PROCEDURE 10: Engine Coolant Temperature Gauge does not Work. (the other meters work).

TECHNICAL DESCRIPTION (COMMENT)

If only the engine coolant temperature gauge does not operate, the engine-A/T-ECU, the combination meter, the wiring harness or its connector may be defective.

TROUBLESHOOTING HINTS

Malfunction of the engine coolant temperature gauge unit

The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.

Malfunction of the combination meter.

DIAGNOSIS PROCEDURE

STEP 1. Check the engine coolant temperature gauge circuit.

Disconnect the B-109 engine coolant temperature gauge unit connector.

Connect a test lamp (12 V - 3.4 W to 12 V - 7.0 W) to the wiring harness side connector.

Ignition switch: ON

Q: Does the test lamp illuminate?

YES: Go to Step 5

.
NO: Go to Step 2

STEP 2. Connector check: Combination meter connector C-04 and engine coolant temperature gauge unit connector B-109.

Q: Is combination meter connector C-04 and engine coolant temperature gauge unit connector B-109 in good condition?

YES: Go to Step 3

.
NO: Repair or replace the damage component(s).

STEP 3. Retest the system.

Q: Is the engine coolant temperature gauge normal?

YES: The procedure is complete. (If no malfunctions are found in all steps, 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 4

STEP 4. Check the wiring harness between combination meter connector C-04 (terminal 44) and engine coolant temperature gauge unit connector B-109 (terminal 1).

NOTE: Prior to the wiring harness inspection, check intermediate connectors C-104, and repair if necessary.

Q: Is the wiring harness between combination meter connector C-04 (terminal 44) and engine coolant temperature gauge unit connector B-109 (terminal 1) in good condition?

YES: Go to Step 6

.
NO: Repair or replace the damage component(s).

STEP 5. Check the engine coolant temperature gauge circuit.

Disconnect the B-109 engine coolant temperature gauge unit connector.

Connect a test lamp (12 V - 3.4 W to 12 V - 7.0 W) to the wiring harness side connector.

Ignition switch: ON

Q: Does the engine coolant temperature gauge in the combination meter fluctuate about half of it full scale?

YES: Replace the engine coolant temperature gauge unit.
NO: Go to Step 6

STEP 6. Retest the system

Q: Is the engine coolant temperature gauge normal?

).
NO: Replace the combination meter.



INSPECTION PROCEDURE 10: Engine Coolant Temperature Gauge does not Work. (the other meters work).


TECHNICAL DESCRIPTION (COMMENT) If only the engine coolant temperature gauge does not operate, the engine-A/T-ECU, the combination meter, the wiring harness or its connector may be defective.
TROUBLESHOOTING HINTS Malfunction of the engine coolant temperature gauge unit The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector. Malfunction of the combination meter.
	DIAGNOSIS PROCEDURE

	STEP 1. Check the engine coolant temperature gauge circuit. Disconnect the B-109 engine coolant temperature gauge unit connector.
	Connect a test lamp (12 V - 3.4 W to 12 V - 7.0 W) to the wiring harness side connector. Ignition switch: ON Q: Does the test lamp illuminate? YES: Go to Step 5. NO: Go to Step 2.
	STEP 2. Connector check: Combination meter connector C-04 and engine coolant temperature gauge unit connector B-109. Q: Is combination meter connector C-04 and engine coolant temperature gauge unit connector B-109 in good condition? YES: Go to Step 3 . NO: Repair or replace the damage component(s).
	STEP 3. Retest the system. Q: Is the engine coolant temperature gauge normal? YES: The procedure is complete. (If no malfunctions are found in all steps, 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 4.
	STEP 4. Check the wiring harness between combination meter connector C-04 (terminal 44) and engine coolant temperature gauge unit connector B-109 (terminal 1). NOTE: Prior to the wiring harness inspection, check intermediate connectors C-104, and repair if necessary. Q: Is the wiring harness between combination meter connector C-04 (terminal 44) and engine coolant temperature gauge unit connector B-109 (terminal 1) in good condition? YES: Go to Step 6 . NO: Repair or replace the damage component(s).
	STEP 5. Check the engine coolant temperature gauge circuit. Disconnect the B-109 engine coolant temperature gauge unit connector.
	Connect a test lamp (12 V - 3.4 W to 12 V - 7.0 W) to the wiring harness side connector. Ignition switch: ON Q: Does the engine coolant temperature gauge in the combination meter fluctuate about half of it full scale? YES: Replace the engine coolant temperature gauge unit. NO: Go to Step 6.
	STEP 6. Retest the system Q: Is the engine coolant temperature gauge normal? YES: The procedure is complete. (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points-How to Cope with Intermittent Malfunction ). NO: Replace the combination meter.