P0117 on Cadillac
Engine Coolant Temperature Sensor Circuit Low
P0117 on Cadillac vehicles indicates engine coolant temperature sensor circuit low. Au7o has documented this code across 1 Cadillac model — most commonly on DTS. This code means the engine coolant temperature (ECT) sensor is reading too low a voltage, which the computer interprets as an impossibly high coolant temperature. In most cases this is an electrical fault — such as a short to ground in the wiring — rather than the engine actually overheating. The coolant temperature signal affects fuel mixture, cooling fans, and other functions, so a bad reading can cause poor running, hard starting, or fans running constantly. The fault is usually in the sensor or its wiring. Typical repair costs on Cadillac range from $2,000 to $4,500, depending on the specific model and root cause.
Common Causes of P0117
- •Faulty engine coolant temperature sensor
- •Short to ground in the sensor signal wire
- •Damaged or corroded wiring/connector at the sensor
- •Coolant contamination affecting the sensor
- •Poor electrical ground
- •Faulty PCM/ECM (less common)
P0117 on Cadillac by Model
Cadillac DTS(1 issue)
- Northstar 4.6L Head Bolt Thread Pull/Head Gasket Failure2000-2005
The Northstar 4.6L V8 in the DTS (and predecessor DeVille) has a well-documented design flaw where the aluminum block head bolt threads strip out, causing head gasket failure. The head gasket itself does not fail; instead the head bolts lose clamping force as the threads pull from the soft aluminum block. The problem is most severe on 1996-2003 engines. GM improved the bolt design in 2000 (longer bolts) and again in 2004 (coarser thread pitch). The Time-Sert thread repair is the accepted permanent fix.
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View P0117 across all makes →Frequently Asked Questions
What does P0117 mean on Cadillac?▼
P0117 stands for "Engine Coolant Temperature Sensor Circuit Low." This code means the engine coolant temperature (ECT) sensor is reading too low a voltage, which the computer interprets as an impossibly high coolant temperature. In most cases this is an electrical fault — such as a short to ground in the wiring — rather than the engine actually overheating. The coolant temperature signal affects fuel mixture, cooling fans, and other functions, so a bad reading can cause poor running, hard starting, or fans running constantly. The fault is usually in the sensor or its wiring. On Cadillac specifically, this code is documented across 1 model.
What causes P0117 on Cadillac vehicles?▼
Common causes on Cadillac: Faulty engine coolant temperature sensor, Short to ground in the sensor signal wire, Damaged or corroded wiring/connector at the sensor, Coolant contamination affecting the sensor, Poor electrical ground. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0117 on a Cadillac?▼
Repair costs on Cadillac range from $2,000 to $4,500, depending on the specific model and root cause.
Which Cadillac models have P0117 documented?▼
Au7o has documented P0117 on 1 Cadillac model: DTS.