Pcm Code E073, Intermittent Coolant Sensor Signal: Action

PCM Code E073 has been set. No service message is given.

1. A DVOM or high impedance digital voltmeter may be used to look for changes too fast to be displayed through PCM data EDO4. To monitor voltage, jumper harness terminals "A" and "B" to sensor terminals "A" and "B". Temperature and coolant sensor voltage (see graph) should match expected temperature at hot idle. If temperature reading has shifted, replace coolant sensor and retest (codes cannot be set or duplicated while in diagnostic mode).
2. A "Scan" tester or DVOM can alternately be used to observe changes in readings.
3. Since coolant temperature cannot change rapidly, a sudden change which occurs at idle as engine is warming up or idling hot most likely indicates a faulty coolant sensor. A loose terminal or connection may cause a change in resistance of circuit.