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DTC P0170 - Fuel Injection System

  1. Check Exhaust/Intake Air Leak  - Start engine and run at idle. Listen for leaks in exhaust system before three way catalyst. Listen for leaks in intake system after MAF sensor. Repair or replace faulty components as required. If no leaks are detected, go to next step.
  2. Check Front HO2S  - Turn ignition off. Disconnect front HO2S harness connector and ECM harness connector. Using an ohmmeter, check for continuity as follows:
    • Between ECM harness connector terminal No. 46 and front HO2S harness connector terminal No. 2 (White wire). Continuity should be present.
    • Between ground and ECM harness connector terminal No. 46. Continuity should not be present.
    • Between ground and front HO2S harness connector terminal No. 2 (White wire). Continuity should not be present.

    If continuity is not as specified, repair fault in White wire circuit. If continuity is as specified, go to next step.

  3. Check Fuel Pressure  - Turn ignition to switch to OFF position. Relieve fuel pressure. See N - REMOVAL/INSTALL/OVERHAUL article. Install fuel pressure gauge. With ignition on, fuel pressure should be about 43 psi (3.0 kg/cm2 ). At idle, fuel pressure should be about 34 psi (2.4 kg/cm2 ). If fuel pressure is not as specified, check for fault in fuel pump and related circuitry. If fuel pressure is okay, inspect MAF sensor. See DTC P0100 - MASS AIRFLOW (MAF) SENSOR  and go to next step.
  4. Check Injectors  - Turn ignition on. Using a voltmeter, check for battery voltage at ECM terminals No. 102 (Red/Black wire), 104 (Green/Black wire), 107 (Yellow/Black wire) and 109 (Blue/Black wire). If battery voltage does not exist, repair fault in wires as required. If battery voltage exists, go to next step.
  5. Remove injector assembly. Keep all associated fuel lines connected. Disconnect CMP sensor harness connector. Turn ignition on. Verify fuel is not dripping from injectors. Replace injectors which are leaking. If no injectors are faulty, go to next step.
  6. Check ECM pins and terminals for damage and check connection of ECM harness connector. Reconnect ECM harness connector and retest.
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