All codes › P0118
P0118: Engine Coolant Temperature Circuit High
What it means
The coolant temp sensor signal is too high (reads as frozen).
Severity: Medium Hard starting and rich running when the engine is warm.
Common causes
- Unplugged sensor
- Open wire
- Failed sensor
- Bad sensor ground
Most common causes first. Exact causes vary by make, model and engine.
Can I fix it myself?
Often DIY. Check for a broken wire at the sensor; replacement is simple.
Repair cost
SEEDED ESTIMATE Roughly $40–$210
Most likely repair: coolant temperature sensor. Diagnosis fees, taxes and other causes are not included.
| Line | Low | High | Basis |
|---|---|---|---|
| Coolant temperature sensor | $12 | $50 | Typical listed retail range, source |
| Labor 0.3–1 hr | $30 | $160 | $100–$160/hr, shop survey |
⚠️ This is an editorial placeholder range for this type of repair. It is not based on real invoices or licensed pricing data yet. Real ranges will appear here once enough reader invoices for P0118 are verified.
Verified reader invoices for P0118: 0. Share your repair bill to help build real costs.
Tools that can read P0118
- ScanFixAI: Pro $29.99/mo or $249.99/yr
- OBDAI: Annual PRO bundle $299
- BlueDriver Pro Next-Gen: $119.95 list ($99.95 sale seen)
The Check Engine Weekly
One email a week: new AI diagnostic tools, real repair costs from reader invoices, and one code explained.
Newsletter launching soon.