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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 448 (Engine Controls Self-Diagnostics - 6.0L Bi-Fuel & CNG) >> Diagnostic Tests >> DTC P1209: FICM Diagnostic Output PWM Signal Not Received By Pcm >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. 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) diagnostic circuit status. Does the scan tool display FAULT? If yes, go to next step. If no, go to step  4.
  3. Are any of the DTCs P0187, P0188, P0191, P0192, P0193, P0611, or P1208 also set? If yes, see INTERMITTENT CONDITIONS  under SELF-DIAGNOSTIC SYSTEM. If no, 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 PCM harness connector C2. Turn ignition on, with engine off. Measure the voltage from the FICM diagnostic output PWM circuit with a DVOM. Does the DVOM display 5.0 volts? If yes, go to step  9. 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 FICM diagnostic output PWM circuit. Did you find and correct an open, or a short to ground? If yes, go to step  13. If no, go to step  10.
  8. Test for a short to voltage on the FICM diagnostic output PWM circuit. Did you find and correct a short to voltage? If yes, go to step  13. If no, go to step  12.
  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 step  13.
  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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