Code 6, Coolant (TW) Sensor
- Turn ignition off. Remove clock fuse in the under-hood relay box for 10 seconds to reset ECU. Start engine and observe PGM-FI warning light. If light is off, problem is intermittent. Test drive and check again.
- If light is on, warm engine to normal operating temperature (cooling fan comes on). Disconnect 2-wire coolant sensor connector. Measure resistance across sensor terminals.
- If resistance is not 200-400 ohms, replace TW sensor. If resistance is within specification, measure voltage between ground and Yellow/Green wire of sensor harness. If reading is not about 5 volts, go to step 5). If reading is about 5 volts, measure voltage between Yellow/Green (pos.) and Green/White wires of connector harness.
- If voltage is not about 5 volts, repair open Green/White (neg.) wire between ECU terminal C12 and sensor. If voltage reading is correct, substitute a known good ECU. If condition is rectified, replace original ECU.
- If voltage between ground and Yellow/Green wire of sensor harness did not read 5 volts in step 3), turn ignition off. Connect system checker harness between ECU and ECU connector. Turn ignition on. measure voltage between terminals C6 (pos.) and C12 (neg.) if voltage reading is about 5 volts, repair open Yellow/Green wire between ECU terminal C6 and TW sensor.
- If reading is not about 5 volts, disconnect "C" connector from main wire harness only, not the ECU. Measure voltage between terminals C6 (pos.) and C12 (neg.). If reading is not about 5 volts, go to next step. If voltage reading is about 5 volts, repair short in Yellow/Green wire between ECU terminal C6 and sensor or repair short in Yellow/Green wire between TW sensor and automatic transmission control unit.
- If voltage reading is still not about 5 volts, substitute a known good ECU. If condition is rectified, replace original ECU.