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P0117 on BMW 5 Series

Engine Coolant Temperature Sensor 1 Circuit Low

Factory diagnostic protocol and troubleshooting wire for fault code P0117 specifically for the BMW 5 Series (2020–2026, 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV).

Verified OEM Telemetry & Field Repair Tree
BMW 5 Series2020–2026
BMW 5 Series
Sedan2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
5 Series 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 BMW Model:
Diagnose P0117 on Specific 5 Series Model Year:

1. Symptoms of P0117 on BMW 5 Series

When the Engine Control Module (ECM/PCM) on your BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV) logs fault code P0117, drivers commonly observe:

Check Engine Light on on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Radiator radiator fans running constantly at high speed on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Temperature gauge pegged at maximum H or not reading on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Engine hard starting when cold (flooding from excess fuel) on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Poor gas mileage and rough idling on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
BMW 5 Series OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower kick panel near hood release lever. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on BMW 5 Series

Historical warranty claims and technical repair bulletins for BMW 5 Series point to the following failure distribution:

55%
ECT sensor internal short to ground (BMW OEM Part)
25%
Short circuit to ground in ECT signal wiring harness (BMW OEM Part)
12%
Damaged, corroded, or water-contaminated ECT connector (BMW OEM Part)
8%
Faulty PCM / ECM analog input circuit (BMW OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for BMW 5 Series.

3. Step-by-Step DIY Repair Guide for BMW 5 Series

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 BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

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 BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

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 BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

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 BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

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 BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

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

Equipment for Diagnosing BMW 5 Series (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 BMW 5 Series.

$34 – $65 Prime
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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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Other Common Fault Codes on BMW 5 Series

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the BMW 5 Series:

4. BMW 5 Series P0117 FAQs

What causes code P0117 to trigger on a BMW 5 Series?

On the BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV), 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 BMW 5 Series?

On the BMW 5 Series, the 16-pin DLC diagnostic connector is located Driver lower kick panel near hood release lever. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my BMW 5 Series 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.