X63 - Check ECT and TP Inputs

- Key "OFF".

- Breakout box installed.

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

- 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.
- ECT voltage should be greater than 0.3 volt (refer to Pinpoint Test DA for ECT voltage chart). DA - Sensor Data

- Check Throttle Position (TP) input:
- Measure voltage between test pin 47 and test pin 40 at the breakout box.
- At closed and part throttle, the TP voltage should stay below 4.5 volts (refer to Pinpoint Test DH for TP voltage chart).

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

Yes -- Replace PCM. Remove breakout box. Reconnect all components. Re-evaluate symptom.

No -- Perform EEC-IV Quick Test (Refer to Diagnostic Routines Symptom Flow Chart, number 32). 32 - No Symptoms Present EEC-IV Quick Test

Service any Diagnostic Trouble Codes (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.