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 powertrain control module
- 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: Vehicle Communication Interface (VCI)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A (Vehicles with CAN communication system)
- 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 89: Fuel gauge
- Fuel gauge unit resistance value and MUT-III displayed value agree with each other
- Item 8A: Fuel gauge (Target)
- Fuel gauge and MUT-III displayed values 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
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. Turn the ignition switch to the "ON" position
3. Set scan tool MB991958 to the actuator test mode
- Item 8C: Fuel Gauge: 0%
- Fuel gauge shows 0 %
- Item 8D: Fuel Gauge: 50%
- Fuel gauge shows 50 %
- Item 8E: Fuel Gauge: 100%
- Fuel gauge shows 100 %
4. 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-17 for loose, corroded or damaged terminals, or terminals pushed back in the connector
Q: Is fuel level sensor (sub) connector D-17 in good condition?
YES: Go to Step 4
NO: Repair or replace the damaged component(s) Refer to, Harness Connector Inspection The combination meter work 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 in Fuel Tank)
STEP 5 Check fuel pump module connector D-18 for loose, corroded or damaged terminals, or terminals pushed back in the connector
Q: Is fuel pump module connector D-18 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 work 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 in 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-17
1. Disconnect fuel level sensor (sub) connector D-17 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
STEP 8 Check powertrain control module connector B-20 for loose, corroded or damaged terminals, or terminals pushed back in the connector
Q: Is powertrain control module connector B-20 in good condition?
YES: Go to Step 9
NO: Repair or replace the damaged component(s) Refer to, Harness Connector Inspection Verify that the combination meter work normally
STEP 9 Check the wiring harness between fuel level sensor (sub), the fuel pump module and the powertrain control module for short to ground Measure the resistance at fuel level sensor (sub) connector D-17
1. Disconnect powertrain control module connector B-20, fuel level sensor (sub) connector D-17 and fuel pump module connector D-18, and measure the resistance available at the harness side of the fuel level sensor (sub) connector D-17
2. Measure the resistance between fuel level sensor (sub) connector D-17 terminal 1 and ground
- The resistance should be 1 k Ohm: or more
Q: Is the measured resistance 1 k Ohm: or more?
YES: Replace powertrain control module When the powertrain control module is replaced, register the encrypted code.
NO: Go to Step 10
STEP 10 Check the wiring harness between fuel level sensor (sub) connector D-17 (terminal 1) and fuel pump module connector D-18 (terminal 2)
Q: Is the wiring harness between fuel level sensor connector D-17 (terminal 1) and fuel pump module connector D-18 (terminal 2) in good condition?
YES: Go to Step 11
NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector Repair the wiring harness as necessary Verify that the combination meter work normally
STEP 11 Check the wiring harness between fuel level sensor (sub) connector D-17 (terminal 1) and powertrain control module connector B-20 (terminal 24)
NOTE: Also check intermediate connector C-25 for loose, corroded, or damaged terminals, or terminals pushed back in the connector If intermediate connector C-25 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection
Q: Is the wiring harness between fuel level sensor connector D-17 (terminal 1) and powertrain control module connector B-20 (terminal 24) in good condition?
YES: An intermittent malfunction is suspected Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction.
NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector Repair the wiring harness as necessary Verify that the combination meter work normally
STEP 12 Check combination meter connector C-101 for loose, corroded or damaged terminals, or terminals pushed back in the connector
Q: Is combination meter connector C-101 in good condition?
YES: Go to Step 13
NO: Repair or replace the damaged component(s) Refer to, Harness Connector Inspection Verify that the combination meter work normally
STEP 13 Check the wiring harness between combination meter and the fuel level sensor (sub) for short to ground Measure the resistance at combination meter connector C-101.
1. Disconnect combination meter connector C-101 and fuel level sensor (sub) connector D-17, and measure the resistance available at the harness side of the combination meter connector C-101
2. Measure the resistance between combination meter connector C-101 terminal 13 and ground
- The resistance should be 1 k Ohm: or less
Q: Is the measured resistance 1 k Ohm: or less?
YES: Go to Step 15
NO: Go to Step 14
STEP 14 Check the wiring harness between combination meter connector C-101 (terminal 13) and fuel level sensor (sub) connector D-17 (terminal 2)
NOTE: Also check intermediate connector C-28 for loose, corroded, or damaged terminals, or terminals pushed back in the connector If intermediate connector C-28 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection
Q: Is the wiring harness between combination meter connector C-101 (terminal 13) and fuel level sensor connector D-17 (terminal 2) in good condition?
YES: An intermittent malfunction is suspected Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction P00-14
NO: The wiring harness may be damaged or the connector may have loose, corroded or damaged terminals, or terminals pushed back in the connector Repair the wiring harness as necessary Verify that combination meter work normally
STEP 15 Retest the system
Check to see that the fuel gauge operates normally
Q: Is the check result satisfactory?
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