Test TC-128A - Closed Loop Temp Not Reached
NOTE:
For connector terminal idnetification, see CONNECTOR IDENTIFICATION DIRECTORY table. For wiring diagram, see WIRING DIAGRAMS article.
- This test procedure is not valid if thermostat is stuck open. If thermostat is operating correctly, go to next step. If thermostat is not operating correctly, replace thermostat. Perform TEST VER-2A .
- CLOSED LOOP TEMP NOT REACHED DTC sets if engine temperature does not rise to more than 60°F (16°C) within 10 minutes after engine is started. Possible causes are: thermostat failure, Engine Coolant Temperature (ECT) failure, extremely cold ambient temperature conditions or Powertrain Control Module (PCM) failure. Go to next step.
- Turn ignition off. Disconnect PCM connector. Inspect PCM connector for damaged or pushed out terminals. Repair PCM connector as necessary. Perform TEST VER-2A . If PCM connector is okay, go to next step.
- Using an external ohmmeter, connect one ohmmeter lead to PCM connector terminal No. 26 ECT sensor signal circuit. Connect other ohmmeter lead to PCM connector terminal No. 43 ECT sensor ground circuit. See PCM TERMINALS 26 & 43 CONNECTOR WIRE IDENTIFICATION table. If resistance is less than 11 k/ohms, replace PCM. Perform TEST VER-2A . If resistance is 11 k/ohms or more, replace ECT sensor. Perform TEST VER-2A .
PCM TERMINALS 26 & 43 CONNECTOR WIRE IDENTIFICATION
| Application | Wire Color |
|---|---|
| PCM Terminal No. 26: (ECT Sensor Signal Circuit) | Tan/Black |
| PCM Terminal No. 43: (ECT Sensor Ground Circuit) | Black/Light Blue |