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
|
| • | Do not use the DTC tables. If a fault is an intermittent, the
use of 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.
| • | Check the suspected circuit for the following conditions: |
| - | Connectors poorly mated |
| - | Terminals not fully seated in the connector body (backed out) |
| - | Terminals improperly formed or damaged |
| - | Terminal to wires poorly connected |
| • | Carefully reform all the connector terminals in the problem circuit
in order to ensure the proper contact tension. If necessary replace all the
connector terminals in the problem circuit in order to ensure the proper contact
tension. |
| • | Checking for poor terminal to wire connections requires removing
the terminal from the connector body in. Refer to the Wiring Repairs
in Engine Electrical. |
|
Road Test
| If a visual and physical
check does not locate the cause of the problem, drive the vehicle with a 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
an intermittent MIL and no DTC(s):
| • | A defective relay, Control Module driven solenoid, or a switch
that can cause an 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, 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 a ground. |
| • | The Malfunction Indicator Lamp (MIL) circuit or the Diagnostic
Test Terminal intermittently shorted to a ground. |
| • | The Control Module grounds. |
|
Loss of
DTC Memory
|
- In order to check for the loss of the DTC Memory, disconnect the
Throttle Position (TP) sensor.
- Idle the engine until the Malfunction Indicator Lamp illuminates.
- The VCM should store a Throttle Position DTC.
- The Throttle Position DTC should remain in the memory when turning
off the ignition.
- If the Throttle Position DTC does not store and remain, the Control
Module is faulty.
|
Additional
Checks
| Check for an open
diode across the A/C compressor clutch and for other open diodes. Refer to
the Wiring Diagrams.
|
