Inspection Procedure 9: Fuel Gauge does not work (other meters work).




COMMENTS ON TROUBLE SYMPTOM


If only the fuel gauge does not operate, the fuel pump and gauge unit, the combination meter, wiring harness or connector(s) may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-13 fuel pump and gauge unit connector

Q. Is the check result normal?

Go to Step 2.

Repair the connector, and then go to Step 9.

STEP 2. Check the fuel gauge circuit.

(1)Disconnect fuel pump and gauge unit connector C-13.

(2)Use the special tool Check harness (MB991219) to connect a test lamp (12 V - 3.4 W) between the wiring harness connector terminals 4 and 5.
(3)Turn the Ignition switch to "ON" position.
(4)Check if the test lamp illuminates.
OK: Illuminates

Q. Is the check result satisfactory?

Go to Step 8.

Go to Step 3.

STEP 3. Resistance measurement at fuel pump and gauge unit connector C-13.

(1)Disconnect fuel pump and gauge unit connector C-13, and measure at the wiring harness side.
(2)Turn the Ignition switch to "LOCK" (OFF) position.

(3)Continuity between fuel pump and gauge unit connector C-13 terminal No.4 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

STEP 4. Check the wiring harness wire between fuel pump and gauge unit connector C-13 terminal No.4 and body earth.


  • Check the earth wires for open circuit.

Q. Is the wiring harness between fuel pump and gauge unit connector C-13 terminal No.4 and body earth in good condition?

Go to Step 5.

Repair the harness, and then go to Step 9.

STEP 5. Connector check: B-19 combination meter connector and C-13 fuel pump and gauge unit connector



Q. Is the check result satisfactory?

Go to Step 6.

Repair the connector, and then go to Step 9.

STEP 6. Check the wiring harness between combination meter connector B-19 terminal No.17 and fuel pump and gauge unit connector C-13 terminal No.5.




  • Check the input line for open or short circuit.

Q. Is the wiring harness between combination meter connector B-19 terminal No.17 and fuel pump and gauge unit connector C-13 terminal No.5 in good condition?

Go to Step 7.

Repair the harness, and then go to Step 9.

STEP 7. M.U.T.-III actuator test

  • Item 11: Fuel gauge(Target): 0 %
  • Item 12: Fuel gauge(Target): 50 %
  • Item 13: Fuel gauge(Target): 100 %
OK: The fuel gauge operates.

Q. Is the check result satisfactory?
Go to Step 8.
After the combination meter is replaced, then perform the variant coding (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ). Then go to Step 9.

STEP 8. Retest the system.
Check that the fuel gauge works normally.

Q. Is the check result satisfactory?
The procedure is complete.
Replace the fuel pump and gauge unit, and the go to Step 9.

STEP 9. Retest the system.
Check that the fuel gauge works normally.

Q. Is the check result satisfactory?
The procedure is complete.
Return to Step 1.