FixGMC Sierra 1500 Check Engine Light On — What It Usually Means, and What It Costs
Across all vehicles, the most common cause of a check engine light is Spark Plugs (17.4%). On the GMC Sierra 1500 it is Sensor (20.3%), so the order of suspects is different for this vehicle. The table below shows each fix for this vehicle next to the all-vehicle share, with what it costs on the GMC Sierra 1500.
What it actually turns out to be on the GMC Sierra 1500
| The fix involved | GMC Sierra 1500* | All vehicles* | Typical cost† |
|---|---|---|---|
| Sensor | 20.3% | 14.2% | $231 – $476 |
| EVAP Component | 18.2% | 9.8% | $224 – $413 |
| Spark Plugs | 16.2% | 17.4% | $212 – $599 |
| Oxygen Sensor | 12.5% | 11.7% | $210 – $435 |
| Fuel Pump | 5.1% | 1.9% | $573 – $1,038 |
| Exhaust Component | 5% | 4% | $147 – $541 |
| Throttle Body | 4.4% | 2.9% | $342 – $685 |
| Catalytic Converter | 3.8% | 3.3% | $499 – $1,141 |
| Fuel Injectors | 3.7% | 2.8% | $136 – $567 |
| Other, rarer causes | smaller shares | — | varies |
*Share of visits whose repair involved this part, among visits for this complaint that ended in a parts repair. Combined
repairs count toward each part involved, so shares overlap and don't add up to 100%.
†Middle half of real GMC Sierra 1500 invoices (25th–75th percentile) when this was the only fix, parts + labor; rows marked "all vehicles" use all vehicle types.
Real repair reports
Recent, paid GMC Sierra 1500 visits for this complaint — the words as the owner said them, and what it turned out to be.
GMC Sierra 1500 owners said
“Diagnose check engine light”
“Diag check engine light/ p0420”
“Diagnose Check Engine Light/ Test Sensors/ Test Drive”
“Check engine light diaganostic”
More on this problem and this vehicle
- Check Engine Light On: all vehicles — how to tell the causes apart, and what each fix usually costs
- All GMC Sierra 1500 repair costs
Take this to the shop
The FixDozer Diagnosis Brief for this complaint puts the all-vehicle odds on one printable sheet. Bring it with this page: the table above shows how the GMC Sierra 1500 differs.
Download the Diagnosis Brief (PDF, all vehicles)View it online · Narrow it down step by step
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