B1201
DTC B1201: Defective fuel gaugeFuel Gauge Circuit Part 1:
Fuel Gauge Circuit Part 2:
CAUTION:
- If DTC B1201 is set in the combination meter, always diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the communication circuit is normal.
CIRCUIT OPERATION
The fuel gauge displays the amount of the remaining fuel on the combination meter.
DTC SET CONDITION
DTC B1201 is set if an open circuit and short to ground in the fuel sender circuit are detected for 64 seconds or more when the ignition switch is ON.
TECHNICAL DESCRIPTION (COMMENT)
The wiring harness or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the combination meter may be defective.
TROUBLESHOOTING HINTS
- Malfunction of ECM
- Malfunction of fuel level sensor (sub).
- Malfunction of fuel pump module.
- Malfunction of 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 (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Using scan tool MB991958, read the MFI system diagnostic trouble code.
Check if an MFI system diagnostic trouble code is set.
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 "ON" position.
3. Read the diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Have any MFI system DTCs set?
YES: Refer to MFI Diagnosis - Diagnostic Trouble Code Chart.
NO: Go to Step 2.
STEP 2. Using scan tool MB991958, check data list.
1. Start the engine.
2. Set scan tool MB991958 to the data reading mode.
- Item 06: fuel gauge (Input).
- Fuel gauge unit resistance value and M.U.T.-III displayed value agree with each other.
- Item 07: fuel gauge (Target).
- Fuel gauge and M.U.T.-III displayed values agree with each other.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result normal?
YES: Go to Step 18.
NO: Go to Step 3.
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 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 Tank). The fuel gauge should now operate normally.
STEP 7. Check the ground circuit to the fuel pump module. Measure the resistance at fuel pump module connector D-19.
1. Disconnect fuel pump module connector D-19 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 9.
NO: Go to Step 8.
STEP 8. Check the wiring harness between fuel pump module connector D-19 (terminal 1) and ground.
Q: Is the wiring harness between fuel pump module connector D-19 (terminal 1) and ground 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 works normally.
STEP 9. Check the wiring harness between fuel level sensor (sub) connector D-10 (terminal 1) and fuel pump module connector D-19 (terminal 2).
1. Disconnect fuel level sensor (sub) connector D-10 and fuel pump module connector D-19, and measure the resistance at the wiring harness side.
2. Measure the resistance between fuel level sensor (sub) connector D-10 terminal 1 and fuel pump module connector D-19 terminal 2.
- The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES: Go to Step 10.
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 works normally.
STEP 10. Check combination meter connector C-04 and ECM
Q: Are combination meter connector C-04 and ECM
YES: Go to Step 11.
NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the combination meter works normally.
STEP 11. Check the wiring harness between combination meter connector C-04 (terminal 16) and fuel level sensor (sub) connector D-10 (terminal 2).
NOTE: Also check intermediate connector C-23 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-23 is damaged, repair or replace the damaged component(s) as described in Harness Connector Inspection.
1. Disconnect combination meter connector C-04 and fuel level sensor (sub) connector D-10, and measure the resistance at the wiring harness side.
2. Measure the resistance between combination meter connector C-04 terminal 16 and fuel level sensor (sub) connector D-10 terminal 2.
- The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES: Go to Step 12.
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 works normally.
STEP 12. 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-04.
1. Disconnect combination meter connector C-04 and fuel level sensor (sub) connector D-10, and measure the resistance available at the harness side of the combination meter connector C-04.
2. Measure the resistance value between terminal 16 and ground.
- The resistance should be 1 k Ohm or more.
Q: Is the measured resistance 1 k Ohm or more?
YES: Go to Step 14.
NO: Go to Step 13.
STEP 13. Check the wiring harness between combination meter connector C-04 (terminal 16) and fuel level sensor (sub) connector D-10 (terminal 2).
NOTE: Also check intermediate connector C-23 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-23 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-04 (terminal 16) and fuel level sensor (sub) connector D-10 (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.
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 works normally.
STEP 14. Check the wiring harness between fuel level sensor (sub), the fuel pump module and the ECM
1. Disconnect fuel level sensor (sub) connector D-10, fuel pump module connector D-19 and ECM
2. Measure the resistance value between terminal 1 and ground.
- The resistance should be 1 k Ohm or more.
Q: Is the measured resistance 1 k Ohm or more?
YES: Go to Step 17.
NO: Go to Step 15.
STEP 15. Check the wiring harness between fuel level sensor (sub) connector D-10 (terminal 1) and fuel pump module connector D-19 (terminal 2).
Q: Is the wiring harness between fuel level sensor connector D-10 (terminal 1) and fuel pump module connector D-19 (terminal 2) in good condition?
YES: Go to Step 16.
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 works normally.
STEP 16. Check the wiring harness between fuel level sensor (sub) connector D-10 (terminal 1) and ECM
NOTE: Also check intermediate connector C-26 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-26 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-10 (terminal 1) and ECM
YES: Go to Step 17.
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 works normally.
STEP 17. Recheck the diagnostic trouble code.
Replace the combination meter, and then check that the diagnostic trouble code is not reset.
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 "ON" position.
3. Erase the diagnostic trouble code.
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Turn the ignition switch to "ON" position.
6. Check if the diagnostic trouble code is set.
7. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result normal?
YES: The procedure is complete.
NO: Replace ECM
STEP 18. Recheck for diagnostic trouble code.
Recheck if the diagnostic trouble code is set.
1. Turn the ignition switch to "ON" position.
2. Erase the diagnostic trouble code.
3. Turn the ignition switch to the "LOCK" (OFF) position.
4. Turn the ignition switch to "ON" position.
5. Check if the diagnostic trouble code is set.
6. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES: The procedure is complete.
NO: Replace combination meter.