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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System (Gasoline) >> Fuel Injector Circuit Diagnosis (4.2L) >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER XL article. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Are any fuel injector DTCs set? If yes, go to DTC P0201-P0206: FUEL INJECTOR CONTROL CIRCUIT under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - 4.2L BRAVADA, ENVOY, ENVOY XL, TRAILBLAZER & TRAILBLAZER XL article. If no, go to next step.
  3. Turn OFF the ignition. Disconnect multi-way harness connector of fuel injectors. Turn ON the ignition, with the engine OFF. Probe Ignition 1 Voltage Supply circuit of fuel injector, fuse side, with test light connected to a good ground. Does test light illuminate? If yes, go to next step. If no, go to step  5.
  4. Test for continuity between Ignition 1 voltage supply terminal and a fuel injector terminal, at multi-way harness connector, fuel injector side. Does DMM display OL? If yes, go to step  6. If no, go to step  7.
  5. Repair open in Ignition 1 Voltage Supply circuit between PCM 1 fuse and multi-way connector. After repairs, go to step  8.
  6. Repair Ignition 1 Voltage Supply circuit of fuel injectors for an open or high resistance, between multi-way connector and splice. After repairs, go to step  8.
  7. Repair poor connection at multi-way harness connector. After repairs, go to next step.
  8. Operate system in order to verify repair. Did you correct the condition? If yes, system is okay. If no, go to step  3.
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