Code No.B1201 Trouble of fuel information

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

POSSIBLE CAUSES

  • Damaged harness wires and connectors
  • Malfunction of fuel tank gauge unit
  • Malfunction of fuel tank pump and gauge unit assembly
  • Malfunction of combination meter

DIAGNOSIS PROCEDURE

Step 1. Connector check: Fuel tank pump and gauge unit assembly connector D-15.

Q. Is fuel tank pump and gauge unit assembly connector C-02 in good condition?

Go to Step 2.

Repair the connector, and then go to Step 11.

Step 2. Check the fuel gauge circuit.

(1)Disconnect fuel tank pump and gauge unit assembly connector D-15.

(2)Use special tool MB991219 to connect a test lamp (12 V - 3.4 W) between the wiring harness connector terminals 1 and 2.
(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 tank pump and gauge unit assembly connector D-15 to check the earth circuit to the fuel tank pump and gauge unit assembly.

(1)Disconnect fuel tank pump and gauge unit assembly connector D-15, and measure at the wiring harness side.
(2)Turn the Ignition switch to "LOCK" (OFF) position.
(3)Disconnect the negative battery terminal.

(4)Measure the resistance value between terminal 1 and earth.
OK: 2 ohms or less

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

Step 4. Check the wiring harness between fuel tank pump and gauge unit assembly connector D-15 (terminal 1) and earth.




note Also check intermediate connector D-28, C-16 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-28, C-16 are damaged, repair or replace the connector.

Q. Is the wiring harness between fuel tank pump and gauge unit assembly connector D-15 (terminal 1) and earth in good condition?

Go to Step 11.

Repair the harness, and then go to Step 11.

Step 5. Connector check: Combination meter connector C-02 and fuel gauge unit connector D-07.



Q. Is combination meter connector C-02 and fuel gauge unit connector D-07 in good condition?

Go to Step 6.

Repair the connector, and then go to Step 10.

Step 6. Check the wiring harness between combination meter connector C-02 (terminal 31) and fuel gauge unit connector D-07 (terminal 1).





note Also check intermediate connectors C-16, D-28 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-16, D-28 are damaged, repair or replace the connector.

Q. Is the wiring harness between combination meter connector C-02 (terminal 31) and fuel gauge unit connector D-07 (terminal 1) in good condition?

Go to Step 7.

Repair the harness, and then go to Step 10.

Step 7. Check the wiring harness between fuel gauge unit connector D-07 (terminal 2) and fuel tank pump and gauge unit assembly connector D-15 (terminal 2).


Q. Is the wiring harness between fuel gauge unit connector D-07 (terminal 2) and fuel tank pump and gauge unit assembly connector D-15 (terminal 2) in good condition?

Go to Step 9.

Repair the harness, and then go to Step 10.

Step 8. M.U.T.-III data list
Item No.8A: Fuel gauge (target value)
OK: Fuel gauge and M.U.T.-III displayed values agree with each other.

Q. Is the check result normal?
Go to Step 11.
Go to Step 9.

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

Q. Is the check result normal?
The procedure is complete.
Replace fuel tank pump and gauge unit assembly and then go to Step 10.

Step 10. Retest the system.
Check that the fuel gauge works normally.

Q. Is the check result normal?
The procedure is complete.
Replace fuel gauge unit and then go to Step 11.

Step 11. Retest the system.
Check that the fuel gauge works normally.

Q. Is the check result normal?
The procedure is complete.
Go to Step 1.