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P0117 on Jeep Grand Cherokee

Engine Coolant Temperature Sensor 1 Circuit Low

Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the Jeep Grand Cherokee (2021–2026, 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

Verified OEM Telemetry & Field Repair Tree
Jeep Grand Cherokee2021–2026
Jeep Grand Cherokee
SUV3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Grand Cherokee SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Not Recommended
High urgency level
Est. Repair Cost
$80 - $250 (DIY: $20 - $60)
Parts & Labor DIY
Check P0117 On Another Jeep Model:
Diagnose P0117 on Specific Grand Cherokee Model Year:

1. Symptoms of P0117 on Jeep Grand Cherokee

When the Engine Control Module (ECM/PCM) on your Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)) logs fault code P0117, drivers commonly observe:

Check Engine Light on on Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP))
Radiator radiator fans running constantly at high speed on Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP))
Temperature gauge pegged at maximum H or not reading on Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP))
Engine hard starting when cold (flooding from excess fuel) on Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP))
Poor gas mileage and rough idling on Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP))
Jeep Grand Cherokee OBD-II Port Location
The 16-pin diagnostic connector is located Under driver side dashboard above foot pedals. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Jeep Grand Cherokee

Historical warranty claims and technical repair bulletins for Jeep Grand Cherokee 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)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Jeep Grand Cherokee.

3. Step-by-Step DIY Repair Guide for Jeep Grand Cherokee

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 the Jeep Grand Cherokee equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

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 the Jeep Grand Cherokee equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

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 the Jeep Grand Cherokee equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

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 the Jeep Grand Cherokee equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

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 the Jeep Grand Cherokee equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

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

Equipment for Diagnosing Jeep Grand Cherokee (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 Grand Cherokee.

$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.

Compare OEM & Aftermarket Replacement Sensors for Jeep Grand CherokeeVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Jeep Grand Cherokee

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Jeep Grand Cherokee:

4. Jeep Grand Cherokee P0117 FAQs

What causes code P0117 to trigger on a Jeep Grand Cherokee?

On the Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)), P0117 is most frequently caused by ECT sensor internal short to ground or Short circuit to ground in ECT signal wiring harness.

Where is the OBD-II port located on my Jeep Grand Cherokee?

On the Jeep Grand Cherokee, the 16-pin DLC diagnostic connector is located Under driver side dashboard above foot pedals. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Jeep Grand Cherokee with code P0117?

No. The ECU thinks the engine is at 280°F+ (overheating) and runs rich or disables cooling fan logic. Given that P0117 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.