FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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KM8 - Check ECT and TP Inputs



- Key "OFF".

- Breakout box installed.

- Reconnect Powertrain Control Module (PCM) to breakout box.

- Reconnect A/C clutch.

- A/C on.

- Start engine.

- Check Engine Coolant Temperature (ECT) input:

- Measure voltage between test pin 7 and test pin 40 at the breakout box.

Engine Coolant/Intake Air Temperature Sensor Values:






- ECT voltage should be greater than 0.3 volt (refer to ECT voltage chart).

- Check Throttle Position (TP) input:

- Measure voltage between test pin 47 and test pin 40 at the breakout box.


Throttle Angle Measurement:






- At closed and part throttle, the TP voltage should stay below 4.5 volts (refer to TP voltage chart).

- Do the ECT and TP input voltages check out OK?

Yes -- Replace PCM. Remove breakout box. Re-evaluate symptom.

No -- Perform EEC-IV Quick Test. Quick Test Appendix (Detailed Testing Instructions)

Service any Diagnostic Trouble Code (DTC) as directed. If OK, check ECT/TP wiring for opens or shorts. Service as necessary. Remove breakout box. Reconnect all components. Re-evaluate symptom.