Inspection Procedure 3
Fuel Gauge does not Work.Fuel Gauge Circuit Part 1:
Fuel Gauge Circuit Part 2:
CIRCUIT OPERATION
- The ignition switch (IG1) circuit is the power source for the fuel gauge.
- The resistance value fluctuates causing the circuit current to fluctuate when the fuel level sensor the float moves up and down.
- The fuel gauge moves the needle by the circuit current.
TECHNICAL DESCRIPTION (COMMENT)
If the ignition switch (IG1) circuit is open, the gauge needle will not move at all. If the ground circuit is open, the gauge needle will move up to its extreme position.
TROUBLESHOOTING HINTS
- Malfunction of the fuel pump module (fuel level sensor)
- Malfunction of the combination meter (printed-circuit board or fuel gauge assembly)
DIAGNOSIS
Required Special Tool:
MB991223: Harness Set
STEP 1. Check the speedometer operation.
Q: Does the speedometer work normally?
YES: Go to Step 2.
NO: Refer to Inspection Procedure 1.
STEP 2. Check the fuel pump module signal circuit at the fuel pump module connector D-17 by back probing.
1. Do not disconnect the fuel pump module connector D-17.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 2 and ground by back probing.
- The measured value should be approximately 5 volts or more.
Q: Does the measured voltage correspond with this range?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check the fuel pump module connector D-17 and combination meter connector C-41 for damage.
Q: Are fuel pump module connector D-17 and combination meter connector C-41 in good condition?
YES: Go to Step 4.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. The fuel gauge should work normally.
STEP 4. Check the wiring harness between fuel pump module connector D-17 (terminal 2) and combination meter connector C-41 (terminal 53).
NOTE: After checking intermediate connector C-90, check the wire. If intermediate connector C-90 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Q: Are the wiring harness between fuel pump module connector D-17 (terminal 2) and combination meter connector C-41 (terminal 53) in good condition?
YES: Repair or replace the combination meter (printed-circuit board or fuel gauge assembly). The fuel gauge should work normally.
NO: Repair or replace the connector. The fuel gauge should work normally.
STEP 5. Check the fuel pump module ground circuit at the fuel pump module connector D-17 by back probing.
1. Do not disconnect the fuel level sensor connector D-17.
2. Measure the resistance between terminal 1 and ground by back probing.
- The measured value should be 2 ohm or less.
Q: Does the measured resistance value correspond with this range?
YES: Go to Step 8.
NO: Go to Step 6.
STEP 6. Check the fuel pump module connector D-17 for damage.
Q: Is fuel level sensor connector D-17 in good condition?
YES: Go to Step 7.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. The fuel gauge should work normally.
STEP 7. Check the wiring harness between fuel pump module connector D-17 (terminal 1) and ground.
Q: Is the wiring harness between fuel pump module connector D-17 (terminal 1)and ground in good condition?
YES: There is no action to be taken.
NO: Repair or replace the connector. The fuel gauge should work normally.
STEP 8. Check the fuel level sensor.
1. Remove the fuel pump module from the fuel tank. (Refer to Fuel Tank).
2. Check resistance value between terminals 2 and 1 is at standard value when the fuel level sensor float is at point "F" (highest) and point "E" (lowest).
3. Check that the resistance value changes smoothly when the float moves slowly between point "F" (highest) and "E" (lowest).
Q: Is the resistance 3 - 5 ohms (at point "F") and 110 - 112 ohms (at point "E")?
YES: Repair or replace the combination meter (printed-circuit board or fuel gauge assembly). The fuel gauge should work normally.
NO: Replace the fuel level sensor. The fuel gauge should work normally.