GM Engine Error Code P1115: How to Fix It

Q: What causes GM P1115 error code?

P1115 is caused by the ECM detecting an intermittent high voltage signal from the ECT sensor. Common causes include a faulty ECT sensor, damaged wiring harness, poor electrical connections, or corrosion in the connector.

Q: Can I drive with P1115 code?

You can drive short distances with P1115, but the engine may run poorly, have rough idling, or show incorrect temperature readings. The ECM may use default values that affect fuel economy and performance. Get it diagnosed and repaired promptly.

Q: How much does it cost to fix P1115?

If it's just a faulty ECT sensor, expect to pay $50-150 for the part plus 1-2 hours of labor. If extensive wiring repair is needed, costs can be $300-600 depending on the extent of damage and labor rates in your area.

Q: Will P1115 cause my car to overheat?

P1115 itself won't cause overheating, but it can prevent accurate temperature monitoring. If the ECT sensor isn't working properly, you might not get early warning of actual overheating conditions, so monitor your temperature gauge closely.

Q: Is P1115 the same as P0117 or P0118?

No, P1115 is specific to GM vehicles and indicates intermittent high voltage, while P0117 is low voltage and P0118 is constant high voltage from the ECT sensor. The diagnosis and repair procedures are similar but the specific conditions are different.

Abstract

GM error code P1115 indicates an intermittent high voltage reading from the Engine Coolant Temperature (ECT) sensor. This can cause poor engine performance, rough idling, and incorrect temperature readings on your dashboard.