Engine Coolant Temperature Sensor Circuit Intermittent (Bank 1)
The P0517 code means the vehicle's onboard diagnostic system has detected: Engine Coolant Temperature Sensor Circuit Intermittent (Bank 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- easy
- Estimated cost
- $30 - $200 (parts and labor)
Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- Check Engine Light on
- Temperature gauge fluctuates erratically
- Cooling fans cycling on and off randomly
- Poor fuel economy during warmup
Probable Causes (Ranked by Likelihood)
- Loose or corroded coolant temperature sensor connector Very High
- Coolant temperature sensor with intermittent internal failure High
- Damaged wiring with intermittent contact near engine heat Moderate
- Poor ECM connector pin contact for temperature circuit Low
Step-by-Step Diagnostic Procedure
-
Wiggle the coolant temperature sensor connector while monitoring live data for signal dropouts
-
Inspect the sensor connector for corrosion, backed-out pins, or coolant contamination
-
Check sensor wiring for heat damage or chafing near exhaust manifold
-
Monitor coolant temperature readings over time with a scan tool for sudden jumps or drops in value
Frequently Asked Questions
What does intermittent mean for P0517?
Intermittent means the ECM has detected that the coolant temperature sensor signal is cutting in and out. Unlike a constant failure, the sensor may work normally some of the time but occasionally drops out or gives erratic readings.
Can a loose connector cause P0517?
Yes. A loose or corroded connector is the most common cause. The vibration of the engine can cause an intermittent connection. Start diagnosis by inspecting and cleaning the connector before replacing the sensor.
Is the coolant temperature sensor expensive?
No. Coolant temperature sensors are typically $15 to $50 for the part and are usually easy to access. The repair can often be done in under an hour.
Sources
This page is built from documented references. Verify against your own service info before repair work.
Explore More
Was this helpful?
Share carcodefinder.com with a friend who needs to decode their check engine light.