Inspection Procedure 9

INSPECTION PROCEDURE 9: Fuel gauge does not work (other meters work).

Fuel Gauge Circuit Part 1:

Fuel Gauge Circuit Part 2:

CIRCUIT OPERATION
- The ignition switch (IG1) circuit is the power supply for the fuel gauge.
- When the float in the fuel level sensor moves, the circuit resistance will change.
- The fuel gauge needle is moved by a change in the circuit current.

TECHNICAL DESCRIPTION (COMMENT)
If only the fuel gauge does not operate, the fuel pump module, the fuel level sensor (sub), the combination meter, wiring harness or connector(s) may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the ECM or PCM
- Malfunction of the fuel level sensor (sub)
- Malfunction of the fuel pump module
- Malfunction of the combination meter
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Using scan tool MB991958, check data list.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Start the engine.
3. Set scan tool MB991958 to the data reading mode.
- Item 06: fuel gauge (Input).
- Fuel gauge unit resistance value and MUT-III displayed value should agree with each other.
- Item 07: fuel gauge (Target).
Fuel gauge and MUT-III displayed values should agree with each other.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result normal?

YES: Go to Step 2.

NO: Go to Step 3.

STEP 2. Using scan tool MB991958, check actuator test.

1. Turn the ignition switch to the "ON" position.
2. Set scan tool MB991958 to the actuator test mode.
- Item 11: fuel gauge (Target): 0%
- Fuel gauge shows 0 %
- Item 8D: fuel gauge (Target): 50%
- Fuel gauge shows 50 %
Item 8E: fuel gauge (Target): 100%
- Fuel gauge shows 100 %
3. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the check result normal?

YES: An intermittent malfunction is suspected. refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.

NO: Replace the combination meter.

STEP 3. Check fuel level sensor (sub) connector D-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is fuel level sensor (sub) connector D-10 in good condition?

YES: Go to Step 4.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. The combination meter works normally.

STEP 4. Check the fuel level sensor (sub).

Check to see if the fuel level sensor (sub) is normal.

Q: Is the fuel level sensor (sub) normal?

YES: Go to Step 5.

NO: Replace the fuel level sensor (Refer to Fuel Supply, Fuel tank).

STEP 5. Check fuel pump module connector D-19 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is fuel pump module connector D-19 in good condition?

YES: Go to Step 6.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the combination meter works normally.

STEP 6. Check the fuel pump module.

Check to see if the fuel pump module is normal.

Q: Is the fuel pump module normal?

YES: Go to Step 7.

NO: Replace the fuel pump module (Refer to Fuel Supply, Fuel tank). The fuel gauge should now operate normally.

STEP 7. Check the ground circuit to the fuel level sensor (sub). Measure the resistance at fuel level sensor (sub) connector D-10.

1. Disconnect fuel level sensor (sub) connector D-10 and measure the resistance available at the harness side of the connector.

2. Measure the resistance value between terminal 1 and ground.
- The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES: Go to Step 8.

NO: Go to Step 12.