Testing & Diagnosis Preliminary Checks
Most driveability problems in the engine control system result from faulty or poor wiring, or loose and/or leaking hose connections. To avoid unnecessary component testing, a visual check should be performed before beginning trouble shooting procedures to help spot these common faults. A preliminary visual check should include:
- Air ducts to air cleaner and from air cleaner to throttle body.
- Electrical connections at all components. Clean, tight and unbroken.
Check vacuum lines for secure, leak-free connections in these areas:
- Throttle body.
- EGR, purge, wastegate and barometric read solenoids (located on a common bracket at right rear corner of engine compartment).
- Vapor canister.
- Vacuum source and fuel pressure regulator.
- PCV valve and turbocharger.
- PCV valve to intake manifold vacuum port.
- Backpressure transducer.
- MAP sensor.
Ensure that the following electrical connectors are securely attached:
- 14-pin and 60-pin connectors at the Single Module Engine Controller (SMEC).
- 3-pin heated O2 sensor connector.
- 2-pin coolant temperature sensor connector.
- Check engine light.
- 2-pin distance sensor connector.
- 3-pin MAP sensor connector.
- 2-pin canister purge solenoid connector.
- 3-pin distributor connector.
- 3-pin Black distributor reference connector.
- 3-pin TPS connector.
- 4-pin AIS motor connector.
- 2-pin throttle body temperature sensor connector.
- 4-pin A/C cut-out relay connector.
- 3 and 1-pin radiator fan relay connector.
- 4-pin ASD relay connector.
- 4-pin and 1-pin barometric read wastegate and purge solenoid connector.
- 2-pin charge temperature sensor connector.