GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Cavalier (CNG) 🢒 Engine 🢒 Engine Controls - 2.2L 🢒 Intermittent Conditions

Checks

Action

DEFINITION: The problem may or may not turn ON the Malfunction Indicator Lamp (MIL) or store a Diagnostic Trouble Code (DTC).

Preliminary Checks
    • Refer to Symptoms .
    • Do not use the DTC tables. If a fault is an intermittent, the use of the DTC tables may result in the replacement of good parts.

Faulty Electrical Connections or Wiring
    • Faulty electrical connections or wiring can cause most intermittent problems.
    • Inspect the suspected circuit for the following conditions:
       - The connectors are poorly mated.
       - The terminals are not fully seated in the connector (backed out).
       - The terminals are not properly formed or the terminals are damaged.
       - The terminal-to-wires are poorly connected.
    • Carefully remove all the connector terminals in the problem circuit in order to ensure the proper contact tension. If needed, replace all the connector terminals in the problem circuit in order to ensure the proper contact tension.
    • In order to inspect for poor terminal to wire connection, you must remove the terminals from the connector body. Refer to Wiring Repairs in Engine Controls - 2.2L in the J Platform Service Manual.

Road Test

If a visual and physical inspection does not locate the cause of the problem, drive the vehicle with the J 39200 connected to a suspected circuit or use a scan tool. When the problem occurs, an abnormal voltage or scan reading indicates the problem may be in that circuit.

Intermittent Malfunction Indicator Lamp (MIL)

The following components can cause intermittent MIL and no DTCs:

    • A defective relay, control module driven solenoid, or a switch that can cause electrical system interference. Normally, the problem will occur when the faulty component is operating.
    • The improper installation of electrical devices, such as lights, 2-way radios, electric motors, etc.
    • Route the ignition control (IC) wires away from the spark plug wires, the ignition system components and the generator. The wire for the engine ground from the control module to the ignition system should be a good ground.
    • The ignition secondary voltage shorted to ground.
    • The malfunction indicator lamp (MIL) circuit or the diagnostic test terminal intermittently shorted to ground.
    • The control module grounds.

Loss of DTC Memory

In order to inspect for the loss of the DTC memory, follow these steps:

  1. Disconnect the throttle position (TP) sensor.
  2. Idle the engine until the malfunction indicator lamp (MIL) illuminates.
  3. The PCM and the ECU should store a throttle position (TP) DTC.
  4. The throttle position (TP) DTC should remain in the memory when turning off the ignition.
  5. If the throttle position (TP) DTC does not store and remain in memory, the control module is faulty.

Additional Checks

Inspect for an open diode across the A/C compressor clutch and for other open diodes. Refer to Engine Controls Schematics in Engine Controls - 2.2L in the J Platform Service Manual.