Code 25 or 26
- Disconnect coolant sensor connector. Connect one lead of an ohmmeter to coolant sensor terminal No. 1. Connect other lead of ohmmeter to terminal No. 2 and then terminal No. 3 of the coolant sensor. If there is some resistance at both terminals, proceed to step 2). If there is resistance at one terminal and not at the other, replace the coolant sensor.
- Ensure sensor connector is disconnected. Disconnect computer 14-pin connector. Connect an ohmmeter between cavity No. 9 of 14-pin connector and terminal No. 3 of coolant sensor connector. If ohmmeter shows continuity, proceed to step 3). If there is no continuity, repair wire for open circuit.
- Disconnect computer 14-pin connector and coolant sensor connector. Connect ohmmeter between cavity No. 11 of 14-pin connector and terminal No. 2 of coolant sensor connector. If ohmmeter shows continuity, ensure terminal in connector cavity No. 11 is not spread apart causing a poor connection. If connection is okay, replace the computer. If there is no continuity, repair wire for open circuit.