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P0117 on RAM: Symptoms, Causes & Fix

Engine Coolant Temperature Sensor 1 Circuit Low

Official technical diagnostic wire for fault code P0117 specifically affecting RAM vehicles (1500, 2500, 3500, TRX).

Sensor Voltage Ref
0.1V – 5.0V Ref
RAM 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 RAM Model for P0117:

5 Models Available

1. Common Symptoms on RAM Vehicles

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

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

2. Root Causes on RAM Engines

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

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

3. Step-by-Step Fix Protocol for RAM

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 RAM 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 RAM 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 RAM 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 RAM 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 RAM engines.

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

Equipment for Diagnosing RAM (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 RAM.

$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 RAMVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
Find Parts on Amazon
* As an Amazon Associate, MazicBay earns from qualifying purchases. Prices & availability subject to change.

4. RAM P0117 Frequently Asked Questions

What does code P0117 mean on a RAM?

On RAM 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 RAM 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 RAM powertrains, we recommend scanning live data values promptly to prevent secondary damage.

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

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