Vectra C 1.8 SRi P0597 and P0115 Fault Code - How to Fix After Replacing Thermostat
I recently diagnosed a Vectra C 1.8 SRi with fault codes P0597 and P0115. The initial P0597 code indicated a coolant circuit thermostat out of range, so I replaced the temperature sensor. However, after replacement, the vehicle now shows P0115 — which appears to be related to the engine coolant temperature sensor (ECT) issue based on online research. I'm wondering what steps I should take to resolve this problem. The car runs normally with no starting issues or misfires. Could the P0115 code be directly linked to the thermostat or sensor replacement? What are the common causes and troubleshooting procedures for this fault in a Vectra C 1.8 SRi?
Check the wiring harness, connectors, and electrical circuit for opens, shorts, or poor grounding. Ensure there is proper voltage supply to the sensor and verify ground connections.