Engine Coolant Level Sensor Circuit Low
The P2557 code means the vehicle's onboard diagnostic system has detected: Engine Coolant Level Sensor Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- easy
- Estimated cost
- $50 - $200 (parts and labor)
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Common Symptoms
- Constant low coolant warning even when full
- Check engine light on
- Coolant gauge may read empty
- Multiple false low-coolant alerts
Probable Causes (Ranked by Likelihood)
- Coolant level sensor stuck in low position Very High
- Short to ground in sensor wiring High
- Heavy coolant contamination fouling sensor Moderate
- Corroded sensor pins creating low resistance path Low
Step-by-Step Diagnostic Procedure
-
Verify coolant level is actually full
-
Clean coolant level sensor probe
-
Test sensor output voltage with coolant at proper level
-
Check sensor wiring for short to ground
Frequently Asked Questions
Why does my car say low coolant when it is full?
P2557 indicates the sensor circuit reads low regardless of actual level. A stuck or contaminated sensor, or a wiring short, causes the false warning.
Can dirty coolant cause P2557?
Yes. Contaminated or old coolant can leave deposits on the sensor probe, causing it to read incorrectly. Flushing the system and cleaning the sensor may help.
Is the coolant level sensor expensive?
The sensor itself is usually $20 to $60. Most of the cost is labor to access and replace it, typically $50 to $200 total.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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