Diagnostic Aids
Check for the following conditions:
- Poor Connection or Damaged Harness. Inspect ECM harness connectors for backed out terminal YD4, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.
- Intermittent Test. If connections and harness check okay, observe ED04 display (coolant temperature) while moving related connectors and wiring harness. If the failure is induced, the coolant temperature display will change. This may help to isolate location of malfunction.
- Shifted Sensor. The temperature-to-resistance value scale may be used to test the coolant sensor at various temperature levels to evaluate the possibility of a shifted (mis-scaled) sensor, which may result in driveability complaints.
A faulty connection, or an open in circuits No. 410 or 452 will result in a Code E015. If Code E023 is also set, check circuit No. 452 for faulty wiring or connections. Check terminals at sensor for good contact.