The APDTY 156629 Engine Coolant Temperature Sensor is a direct-replacement threaded sensor that measures engine coolant temperature and transmits this data to your vehicle's ECM (Engine Control Module). When this sensor fails, you may experience rough idling, poor fuel economy, check engine lights, or inaccurate temperature readings. Part number 156629 replaces OE Ford part F8CZ12A648B and fits select Ford, Mazda, Mercury, and Land Rover models from 1995 to 2017 with specific engine configurations.
Key Takeaways
- Threaded-style engine coolant temperature sensor for ECM signal (not for dashboard temperature gauge)
- Replaces Ford OE part number F8CZ12A648B
- Fits select 1995-2017 Ford, Mazda, Mercury, and Land Rover vehicles with specific engines
- Corrects check engine lights, rough idle, and fuel economy issues caused by failed ECT sensors
- Brand new sensor; verify fitment using the live compatibility chart before ordering
Buy APDTY 156629 directly from APDTY
What Does the Engine Coolant Temperature Sensor Do?
The engine coolant temperature (ECT) sensor is a critical input device for your vehicle's engine control module. It monitors the temperature of the engine coolant and sends a voltage signal to the ECM, which uses this data to:
- Adjust fuel injection timing and air-fuel mixture
- Control ignition timing
- Regulate cooling fan operation
- Determine when the engine is warm enough for closed-loop operation
- Activate cold-start enrichment protocols
Important: APDTY 156629 is the ECT sensor that sends data to the engine computer. It is not the temperature sending unit that drives your dashboard gauge. For the dashboard gauge sender, see APDTY part APD-156630.
What Are the Symptoms of a Failed Coolant Temperature Sensor?
A malfunctioning ECT sensor can cause a wide range of driveability and performance problems, including:
- Check Engine Light: Common codes include P0117 (ECT Circuit Low), P0118 (ECT Circuit High), or P0125 (Insufficient Coolant Temperature)
- Poor Fuel Economy: The ECM may run rich if it believes the engine is always cold
- Rough Idle or Stalling: Incorrect fuel mixture due to bad temperature data
- Hard Starting: Especially when the engine is warm
- Black Smoke from Exhaust: Over-fueling from a sensor stuck in cold mode
- Cooling Fans Running Constantly: ECM may think the engine is overheating
If you experience any of these symptoms and diagnostic trouble codes point to the ECT sensor circuit, replacing the sensor often resolves the issue.
Which Vehicles Does APDTY 156629 Fit?
APDTY part number 156629 is a threaded-style ECT sensor compatible with the following vehicles and engine configurations:
| Year Range | Make | Model | Engine(s) |
|---|---|---|---|
| 1999 | Ford | Contour | 2.0L L4 |
| 1997-2003 | Ford | Explorer | 4.0L V6, 4.6L V8, 5.0L V8 |
| 2001-2003 | Ford | Explorer Sport | 4.0L V6 |
| 2001-2003 | Ford | Explorer Sport Trac | 4.0L V6 |
| 2001 | Ford | F-100 Ranger | 2.3L L4, 3.0L V6 |
| 2008 | Ford | Fiesta | 2.0L L4 |
| 2006-2009 | Ford | Fusion | 2.3L L4 |
| 1996-1997 | Ford | Probe | 2.0L L4, 2.5L V6 |
| 2001-2017 | Ford | Ranger | 2.3L L4, 2.5L L4, 4.0L V6 |
| 2005-2007 | Land Rover | LR3 | 4.0L V6 |
| 1995-2002 | Mazda | 626 | 2.0L L4, 2.5L V6 |
| 1996-1997 | Mazda | MX-6 | 2.0L L4 |
| 1999-2002 | Mercury | Cougar | 2.0L L4 |
| 2008 | Mercury | Mariner | 2.3L L4 |
| 2006-2009 | Mercury | Milan | 2.3L L4 |
| 1998-2004 | Mercury | Mountaineer | 4.0L V6, 4.6L V8 |
| 1997-1999 | Mercury | Mystique | 2.0L L4 |
Important: This sensor is the threaded style only. Some vehicles may use a different sensor design (clip-in or push-in). Always verify your specific year, make, model, and engine using the live compatibility chart on the product page before ordering.
Technical Specifications and OE Cross-Reference
APDTY 156629 is manufactured to OE specifications and designed as a direct replacement for the factory coolant temperature sensor.
| Specification | Detail |
|---|---|
| APDTY Part Number | 156629 |
| Sensor Type | Engine Coolant Temperature (ECT) |
| Mounting Style | Threaded |
| Function | Sends temperature signal to ECM/PCM |
| Replaces OE Part Number | F8CZ12A648B |
| Condition | Brand New |
This sensor uses a thermistor that changes electrical resistance based on coolant temperature. The ECM supplies a reference voltage (typically 5V), and the sensor modulates this signal. As coolant temperature rises, resistance decreases, and the voltage signal changes accordingly.
How to Install the Engine Coolant Temperature Sensor
Replacing the ECT sensor is typically a straightforward job for DIYers with basic mechanical skills. Follow these general steps:
- Safety First: Allow the engine to cool completely before starting. Never open the cooling system on a hot engine—pressurized coolant can cause serious burns.
- Locate the Sensor: The ECT sensor is usually threaded into the engine block, cylinder head, or intake manifold near the thermostat housing. Consult your vehicle's service manual for the exact location.
- Drain Coolant (If Necessary): If the sensor is below the level of coolant in the radiator, drain enough coolant to drop the level below the sensor to minimize spillage.
- Disconnect Electrical Connector: Unplug the wiring harness connector from the old sensor. Some connectors have a release tab or clip.
- Remove Old Sensor: Use an appropriate wrench or socket (often 19mm or 3/4 inch) to unscrew the old sensor. Be prepared for minor coolant spillage.
- Inspect Threads: Check the threads in the engine block for damage or debris. Clean if necessary.
- Install New Sensor: Thread the new APDTY 156629 sensor into place by hand first to avoid cross-threading, then tighten to the torque specification in your service manual (typically 8-12 lb-ft, but verify for your engine).
- Reconnect Wiring: Plug the electrical connector back onto the new sensor until it clicks or locks.
- Refill Coolant: Top off the cooling system with the correct coolant type and mixture for your vehicle. Bleed air from the system per manufacturer procedure.
- Clear Codes and Test: Use an OBD-II scanner to clear any stored trouble codes, then start the engine and verify that the check engine light does not return and that the engine runs normally.
Tip: If you're also performing other cooling system maintenance (thermostat, hoses, flush), this is an ideal time to replace the ECT sensor as preventive maintenance.
Frequently asked questions
Is APDTY 156629 the sensor for my dashboard temperature gauge?
No. APDTY 156629 sends temperature data to the engine computer (ECM/PCM) and does not drive the dashboard gauge. For the gauge sending unit, see APDTY part number APD-156630.
What OE part number does APDTY 156629 replace?
APDTY 156629 replaces Ford OE part number F8CZ12A648B. It is a direct-fit replacement for the factory threaded coolant temperature sensor.
Will this sensor fit my Ford Ranger?
APDTY 156629 fits 2001-2017 Ford Rangers equipped with 2.3L L4, 2.5L L4, or 4.0L V6 engines and the threaded-style sensor. Always verify your specific year and engine using the compatibility chart on the product page.
Can a bad ECT sensor cause my check engine light to come on?
Yes. A failed or malfunctioning coolant temperature sensor commonly triggers check engine codes such as P0117, P0118, or P0125. Scan your vehicle with an OBD-II tool to confirm the code before replacing the sensor.
The APDTY 156629 Engine Coolant Temperature Sensor is a reliable, OE-quality replacement for failed ECT sensors in a wide range of Ford, Mazda, Mercury, and Land Rover vehicles. By restoring accurate temperature readings to your engine computer, this sensor helps eliminate check engine lights, improve fuel economy, and ensure smooth engine performance. Always verify fitment for your specific year, make, model, and engine using the live compatibility chart, and follow proper cooling system safety procedures during installation. Order APDTY 156629 today to get your vehicle running right again.