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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 92 (Engine Controls - Self-Diagnostics - 6.6L Diesel) >> Diagnostic Tests >> DTC P1094: Excessive Fuel Injection Pump Flow >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check-Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Is DTC P1093 also set? If yes, see DTC P1093: FUEL RAIL PRESSURE OUT OF RANGE . If no, go to next step.
  3. Attempt to start the engine. Does the engine start and continue to run? If yes, go to next step. If no, see NO-START - ENGINE CRANKS OKAY (6.6L DIESEL) under NO-START DIAGNOSIS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  4. Is the customer concern also a surging idle? If yes, diagnose fuel system high pressure side. See FUEL SYSTEM DIAGNOSIS - HIGH PRESSURE SIDE under FUEL SYSTEMS (DIESEL) in SYSTEM & COMPONENT TESTING - TRUCKS -EXCEPT TRACKER article. If no, go to next step.
  5. Start and idle the engine. Observe the FRP regulator fuel flow with a scan tool. Does the FRP regulator fuel flow measure more than 12,000 mm3 ? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  6. Test the fuel pressure regulator solenoid control circuit between the ECM and the fuel pressure regulator for a short to ground. Did you find and correct the condition? If yes, go to step  9. If no, go to next step.
  7. Test for an intermittent or poor connection at the ECM. Did you find and correct the condition? If yes, go to step  9. If no, go to next step.
  8. Replace the ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram ECM. See ENGINE CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  9. Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  10. Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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