Engine Cooling System Performance
This code indicates a performance issue in the engine's cooling system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine control unit (ECU) is detecting that the cooling system isn't keeping the engine temperature in the normal range, which can lead to overheating or underheating.
What the computer is actually seeing
The ECU monitors the engine temperature via a coolant temperature sensor, aiming for a range of 190°F to 220°F (88°C to 104°C). If the readings go below 160°F (71°C) or exceed 240°F (116°C) for a certain duration, it triggers this code.
What a healthy reading looks like
Normal coolant temperature should be between 190°F and 220°F (88°C to 104°C).
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the coolant level in the reservoir and radiator; ensure it's at the recommended level. If low, refill and check for leaks. Decision: Is coolant level normal? Yes - go to step 2. No - refill and retest.
Common causes
- Faulty coolant temperature sensor
- Low coolant level
- Malfunctioning thermostat
- Blocked radiator
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Driving with this code is moderate risk; monitor engine temperature closely.
Will this fault come back after clearing it?
If the underlying issue isn't resolved, yes, it will return.
Why does this code sometimes pair with SPN 304?
Both codes are related to coolant temperature management; they often trigger together when the cooling system is failing.
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