What Does P2558 Mean?
The PCM is detecting an abnormally low voltage on the coolant level sensor circuit. This typically indicates the sensor circuit is shorted to ground or the sensor is reading a constant 'low coolant' condition.
Common Causes
35%
Wiring harness shorted to ground between sensor and PCM
30%
Low coolant level causing sensor to read low continuously
25%
Faulty coolant level sensor stuck in low/ground position
7%
Corroded sensor connector causing short circuit
3%
PCM internal circuit fault on sensor input
Diagnostic Steps
1
Step 1: Verify actual coolant level is correct and check for visible coolant leaks
2
Step 2: Disconnect coolant level sensor and check if code clears or changes to circuit open code
3
Step 3: Test sensor signal wire for short to ground by measuring resistance to ground with sensor disconnected
4
Step 4: Inspect wiring routing near exhaust, sharp edges, or moving components for chafed insulation
5
Step 5: Test coolant level sensor operation by checking resistance or continuity change when float is moved
Estimated Repair Cost
$90 - $400
Parts + labor, varies by vehicle and location
The PCM is detecting an abnormally low voltage on the coolant level sensor circuit. This typically indicates the sensor circuit is shorted to ground or the sensor is reading a constant 'low coolant' condition.
The most common cause of P2558 (Engine Coolant Level Sensor/Switch Circuit Low) is: Wiring harness shorted to ground between sensor and PCM
Typical repair costs for P2558 range from $90 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may have actual low coolant condition if level is truly low. Check coolant level immediately to prevent engine damage from overheating.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2558 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Cooling System Monitoring
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
