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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 433 (Engine Controls - Self-Diagnostics - 6.0L Bi-Fuel & CNG) >> Diagnostic Tests >> DTC P1207: Fuel Rail Pressure Output PWM Signal Not Received By Pcm >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Alternative Fuels - Engine Controls. If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ALTERNATIVE FUELS - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Using a scan tool, observe the Fuel Injection Control Module (FICM) odd bank circuit status. Does the scan tool display FAULT? If yes, go to next step. If no, go to step  4.
  3. If DTC P0611 is also set, see DTC P0611: FUEL INJECTOR CONTROL MODULE PERFORMANCE . If DTC P0611 is not set, go to step  5.
  4. Observe the Freeze Frame and/or the Failure records data for this DTC. Turn the ignition off for 30 seconds. Start the engine. Operate the vehicle within the Conditions For Running The DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame and/or the Failure records data. If the DTC failed this ignition cycle, go to next step. If the DTC does not fail this ignition cycle, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM.
  5. Turn ignition off. Disconnect the FICM harness connector. Turn ignition on, with engine off. Using a DVOM, measure the voltage from the PWM output circuit. Does the DVOM display a voltage reading of 5 volts? If yes, go to step  10. If no, go to next step.
  6. If the voltage is more than 5.3 volts, go to step  8. If the voltage is less than 5.3 volts, go to next step.
  7. Test for an open or a short to ground on the PWM output circuit. Did you find and correct an open or a short to ground? If yes, go to step  13. If no, go to step  9.
  8. Test for a short to voltage on the PWM output circuit. Did you find and correct a short to voltage? If yes, go to step  13. If no, go to step  11.
  9. Test for an intermittent and/or a poor connection at the PCM. Did you find and correct an intermittent and/or a poor connection? If yes, go to step  13. If no, go to step  11.
  10. Test for an intermittent and/or a poor connection at the FICM. Did you find and correct an intermittent and/or a poor connection? If yes, go to step  13. If no, go to step  12.
  11. Replace the PCM. After replacement is complete, go to step  13.
  12. Replace the FICM. After replacement is complete, go to next step.
  13. Using a scan tool, clear the DTCs. Turn ignition off for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. If the DTC failed this ignition cycle, go to step  2. If the DTC did not fail this ignition cycle, go to next step.
  14. Observe the Capture Info using a scan tool. Are there any DTCs that have not been diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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