DTC B1201: Abnormal fuel information: Diagnosis
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
- STEP 1. Check the malfunctioning vehicle.
Q: Is the malfunctioning vehicle a FWD?
- YES < FWD >: Go to Step 2.
- NO < AWD >: Go to Step 8.
- STEP 2. Check fuel pump module connector D-20 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is fuel pump module connector D-20 in good condition?
- YES: Go to Step 3.
- NO: Repair the connector.
- STEP 3. Check the fuel level sensor (main).
Check to see if the fuel level sensor (main) is normal. Refer to FUEL GAUGE UNIT CHECK .
Q: Is the check result normal?
- YES: Go to Step 4.
- NO: Replace the fuel level sensor (main).
- STEP 4. Measure the resistance at fuel pump module connector D-20.
- Disconnect pump module connector D-20, and measure at the wiring harness side.
- Measure the resistance value between terminal 1 and ground.
- The measured value should be 2 ohm or less.
Q: Does the measured resistance value correspond with this range?
- YES: Go to Step 6.
- NO: Go to Step 5.
- STEP 5. Check the wiring harness between fuel pump module connector D-20 (terminal 1) and ground.
- Check the ground wire for open circuit.
Q: Is the wiring harness between fuel pump module connector D-20 (terminal 1) and ground in good condition?
- YES: There is no action to be taken.
- NO: Repair the wiring harness.
- Check the ground wire for open circuit.
- STEP 6. Check combination meter connector C-03 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is combination meter connector C-03 in good condition?
- YES: Go to Step 7.
- NO: Repair the connector.
- STEP 7. Check the wiring harness between fuel pump module connector D-20 (terminal 2) and combination meter connector C-03 (terminal 17 or 18).
- Check the communication lines for open circuit and short circuit.NOTE: Also check intermediate connectors C-31 and D-05. If intermediate connectors C-31 and D-05 are damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
Q: Are the wiring harness between fuel pump module connector D-20 (terminal 2) and combination meter connector C-03 (terminal 17 or 18) in good condition?
- YES: Go to Step 14.
- NO: Repair the wiring harness. The fuel gauge should work normally.
- Check the communication lines for open circuit and short circuit.
- STEP 8. Check fuel pump module connector D-20 and fuel level sensor (sub) connector D-22 < AWD > for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is fuel pump module connector D-20 and fuel level sensor (sub) connector D-22 < AWD > in good condition?
- YES: Go to Step 9.
- NO: Repair the connector.
- STEP 9. Check the fuel level sensor (main) and (sub)
Check to see if the fuel level sensor (main) and (sub) is normal. Refer to FUEL GAUGE UNIT CHECK .
Q: Is the check result normal?
- YES: Go to Step 10.
- NO: Replace the fuel level sensor (main) or (sub).
- STEP 10. Measure the resistance at fuel pump module connector D-20.
- Disconnect fuel pump module connector D-20, and measure at the wiring harness side.
- Measure the resistance value between terminal 1 and ground.
- The measured value should be 2 ohm or less.
Q: Does the measured resistance value correspond with this range?
- YES: Go to Step 12.
- NO: Go to Step 11.
- STEP 11. Check the wiring harness between fuel pump module connector D-20 (terminal 1) and ground.
- Check the ground wire for open circuit.
Q: Is the wiring harness between fuel pump module connector D-20 (terminal 1) and ground in good condition?
- YES: There is no action to be taken.
- NO: Repair the wiring harness.
- Check the ground wire for open circuit.
- STEP 12. Check combination meter connector C-03 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is combination meter connector C-03 in good condition?
- YES: Go to Step 13.
- NO: Repair the connector.
- STEP 13. Check the wiring harness between fuel pump module connector D-20 (terminal 2) and combination meter connector C-03 (terminal 17 or 18).
- Check the communication lines for open circuit and short circuit.NOTE: Also check intermediate connectors C-31 and D-05. If intermediate connectors C-31 and D-05 are damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
Q: Are the wiring harness between fuel pump module connector D-20 (terminal 2) and combination meter connector C-03 (terminal 17 or 18) in good condition?
- YES: Go to Step 14.
- NO: Repair the wiring harness. The fuel gauge should work normally.
- Check the communication lines for open circuit and short circuit.
- STEP 14. Using scan tool MB991958, perform actuator test.
- Item 03: Fuel gauge (target value): 0 → 100%
- Fuel gauge shows 100 %
Q: Is the check result normal?
- YES: Go to Step 15.
- NO: Replace the combination meter.
- Item 03: Fuel gauge (target value): 0 → 100%
- STEP 15. Recheck for diagnostic trouble code.
Check again if the DTC is set to the combination meter.
- Erase the DTC.
- Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
- Check if DTC is set.
Q: Is the DTC set?
- YES: Replace the combination meter.
- NO: The procedure is complete.