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P0117 on Jeep: Symptoms, Causes & Fix

Engine Coolant Temperature Sensor 1 Circuit Low

Official technical diagnostic wire for fault code P0117 specifically affecting Jeep vehicles (Grand Cherokee, Wrangler, Gladiator, Compass).

Sensor Voltage Ref
0.1V – 5.0V Ref
Jeep Factory Standard
CAN Bus Speed
500 kbps CAN-FD
ISO 15765-4 Diagnostic Bus
Drivability Status
Not Recommended
High urgency level
Est. Repair Cost
$80 - $250 (DIY: $20 - $60)
Parts & Labor DIY
Model-Specific Diagnostic Wires

Select Your Jeep Model for P0117:

5 Models Available

1. Common Symptoms on Jeep Vehicles

When Jeep Engine Control Modules (ECM) trigger fault code P0117, drivers typically report:

Check Engine Light on on Jeep Powertrains
Radiator radiator fans running constantly at high speed on Jeep Powertrains
Temperature gauge pegged at maximum H or not reading on Jeep Powertrains
Engine hard starting when cold (flooding from excess fuel) on Jeep Powertrains
Poor gas mileage and rough idling on Jeep Powertrains

2. Root Causes on Jeep Engines

Historical diagnostic claims across Jeep engines point to the following failure distribution:

55%
ECT sensor internal short to ground (Jeep OEM Part)
25%
Short circuit to ground in ECT signal wiring harness (Jeep OEM Part)
12%
Damaged, corroded, or water-contaminated ECT connector (Jeep OEM Part)
8%
Faulty PCM / ECM analog input circuit (Jeep OEM Part)

3. Step-by-Step Fix Protocol for Jeep

01
Scan ECT Temperature Data

Read ECT live PID on scanner. If it reads 284°F (140°C) or higher with engine cold, a short to ground exists. on Jeep engines.

Required Tool: OBD-II Scanner
02
Unplug ECT Sensor Connector

Unplug sensor connector while watching live data. If temperature drops to -40°F (-40°C), the sensor itself is shorted. on Jeep engines.

Required Tool: OBD-II Scanner
03
Inspect Wiring Harness

If reading stays pegged at max with sensor unplugged, inspect harness for pinch points grounding against engine block. on Jeep engines.

Required Tool: Digital Multimeter
04
Replace Engine Coolant Temperature Sensor

Allow engine to cool, unscrew old ECT sensor from coolant crossover pipe or thermostat housing, install new OEM sensor with fresh thread sealant. on Jeep engines.

Required Tool: 19mm Deep Socket, Ratchet, Coolant Catch Pan
05
Top off Coolant & Clear Codes

Bleed air from cooling system, clear DTCs, and verify normal temperature rise on live data. on Jeep engines.

Required Tool: Coolant Funnel Kit, OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Jeep (P0117)

Prime Fast Delivery & Verified Fitment
Variable Valve Timing (VVT)

VVT Oil Control Solenoid Valve

4.6 / 5.0 (Direct Fit)

Restores accurate camshaft timing and oil pressure regulation on Jeep.

$34 – $65 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

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4. Jeep P0117 Frequently Asked Questions

What does code P0117 mean on a Jeep?

On Jeep vehicles, P0117 indicates that the Engine Control Module (ECM) detected engine coolant temperature sensor 1 circuit low. This typically points to ECT sensor internal short to ground or Short circuit to ground in ECT signal wiring harness.

Can I continue driving my Jeep with code P0117?

No. The ECU thinks the engine is at 280°F+ (overheating) and runs rich or disables cooling fan logic. Because this code carries a High severity rating on Jeep powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code P0117 on a Jeep?

Estimated DIY parts cost ranges from $80 - $250 (DIY: $20 - $60), while professional shop repairs at an authorized Jeep dealership or independent specialist typically range from $180 to $380 including diagnostic labor.