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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 330 (Engine Controls - Self-Diagnostics - 3.0L) >> Diagnostic Tests >> DTC P2138: App Sensor Correlation >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Saturn Vue. 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, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
  2. Observe the DTC information with a scan tool. Is DTC P0101, P0121, P0122, P0123, P0221, P0222, P0223, P2122, P2123, P2127, or P2128 also set? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Turn ignition off. Disconnect the APP sensor electrical connector. Disconnect the ECM. Measure the resistance of the following circuits with a DVOM for each of the APP sensors: The low reference circuit, signal circuit and 5-volt reference circuit. Is resistance more than 5 ohms for any circuit? If yes, go to step  7. If no, go to next step.
  4. Test the signal circuit of APP sensor 1 for a short to the signal circuit of APP sensor 2. Did you find and correct the condition? If yes, go to step  9. If no, go to next step.
  5. Test for an intermittent and for a poor connection at the APP sensor. Did you find and correct the condition? If yes, go to step  9. If no, go to next step.
  6. Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? If yes, go to step  9. If no, go to step  8.
  7. Repair high resistance in the circuit that measured more than the specified value. After repairs, go to step  9.
  8. Replace APP sensor. After replacing sensor, go to next step.
  9. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  10. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.
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