DTC P1176: Fuel Mass Flow Rate Lean
NOTE:
After each repair, clear DTCs. See CLEARING CODES/PCM RESET PROCEDURE
under SELF-DIAGNOSTIC SYSTEM. Turn ignition off and then on. Read DTCs to verify repair is complete. For DLC and PCM connector terminal identification, see CONNECTOR IDENTIFICATION
. For wiring diagrams, see WIRING DIAGRAMS
.
- Using scan tool, read DTCs. If DTC P1176 is present, turn ignition off. Ensure fuel pump is operating correctly. Repair as necessary. If fuel pump is okay, Remove fuel pump relay and harness connector at fuel pump. Fuel pump relay is located in trunk electrical carrier (XJR and XJ6) or above right rear wheelwell (XJS).
- Using DVOM, check for continuity of Pink/Brown wire between fuel pump relay and PCM Black connector terminal No. 19. On XJR and XJ6, check for continuity of Brown/Yellow wire between fuel pump relay and fuse No. 7 (30-amp), located in right fuse box below right rear seat. On XJS, check for continuity of Brown/Red wire between fuel pump relay and fuse No. 6 (5-amp), located in rear fuse panel at right taillight. Repair wiring as necessary. If wiring is okay, go to next step.
- On XJR and XJ6, check for continuity of White/Pink wire between fuel pump relay and fuse No. 10 (5-amp), located in right fuse box below right rear seat. On XJS, check for continuity of White/Brown wire between fuel pump relay and PCM power relay, located in right component panel. Repair wiring as necessary. If wiring is okay, go to next step.
- On XJR and XJ6, check for continuity of Red/Yellow wire between fuel pump relay and fuel pump, located inside fuel tank. On XJS, check for continuity of Blue/Red wire between fuel pump relay and fuel pump, located inside fuel tank. Repair wiring as necessary. If wiring is okay, check for continuity of Black wire between fuel pump and ground. Repair Black wire as necessary. If wire is okay, go to next step.
- Reconnect fuel pump relay harness connector. Inspect fuel filter for blockage. Repair as necessary. If fuel filter is okay, check for fuel pipe or fuel rail leaks or blockage. Repair as necessary. If fuel pipe and fuel rail are okay, check for low fuel pressure. See the following:
- For 1995 models, see FUEL SYSTEM in BASIC TESTING article.
- For 1996 models, see FUEL SYSTEM in BASIC TESTING article.
- For 1997 XJR models, see FUEL SYSTEM in BASIC TESTING article.
- For 1997 XJ6 models, see FUEL SYSTEM in BASIC TESTING article.
- Check Black/Yellow wires (XJS) or Black/Light Green wires (XJR and XJ6) for short circuit to ground at each fuel injector. Repair wiring as necessary. If wiring is okay, check for MAF sensor or HO2S DTCs. Repair as necessary. If MAF or HO2S DTCs are not present, clear DTCs. Turn ignition off and then on. Read DTCs. If DTC P1176 is not present, repair is complete. If DTC P1176 is present, replace PCM.