DA - Testing Notes

Temperature Sensor Schematic:

DESCRIPTION
The Intake Air Temperature (IAT) and Engine Coolant Temperature (ECT) sensors change resistance in response to temperature. IAT and ECT sensor resistance decreases as the surrounding temperature increases providing a signal to the Powertrain Control Module (PCM) that indicates the temperature of either the incoming intake air or engine coolant temperature.


NOTE
You should enter this pinpoint test only when you have been directed here from Diagnostic Routines.

REMEMBER
To prevent the replacement of good components, be aware that the following non-Electronic Engine Controls (EEC) areas may be at fault:

- Coolant level

- Cooling system

- Cooling Fan

- Water pump drive belt

- Engine operating temperature

- Engine oil level

- Thermostat

- Air cleaner duct

- Ambient temperature

This pinpoint test is intended to diagnose the following:

- IAT sensor (12A697)

- ECT sensor (12A648)

- Harness circuits: IAT, ECT, and SIG RTN

- PCM