Diagnostic Aids
WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.
Enter this test only when directed here from QUICK TEST or another SYSTEM TEST. This test is intended to diagnose the following components and circuits:
- Engine Coolant Temperature (ECT) sensor.
- Intake Air Temperature (IAT) sensor.
- Harness circuits; IAT and ECT.
- PCM.
For DTC P0110 or P0115, ECT or IAT PID reading of 68°F (20°C), resistance across IAT sensor should be 2100-2900 ohms.
For DTC P0125, disconnect ECT sensor circuit connector. Insert a jumper wire between SIG RTN and ECT signal circuits at ECT sensor harness connector with ignition on. ECT PID should read approximately 212°F (100°C).
For DTC P1217, inspect entire cooling system for leaks and check for proper cooling system and cooling fan operation. See SPECIFICATIONS & DRIVE BELT ROUTING - TRUCKS article in ENGINE COOLING. Check for correct operation of ECT sensor.
ENGINE COOLANT & INTAKE AIR TEMPERATURE SENSOR DATA
| Temperature °F (°C) | Output Voltage | Resistance (Ohms) |
|---|---|---|
| 14 (-10) | 4.4 | 9200 |
| 68 (20) | 3.5 | 2500 |
| 122 (50) | 2.2 | 800 |
| 194 (90) | 0.9 | 200 |
ECT, IAT & SIG RTN CIRCUIT IDENTIFICATION
| Circuit | PCM Pin No. | Wire Color |
|---|---|---|
| ECT | 59 | Light Green/Red |
| IAT | 61 | Yellow/Green |
| SIG RTN | 58 | Black/Yellow |