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ERR4278LR - Throttle Potentiometer by Land RoverElectrical Part Land Rover Range Rover Defender, Discovery, Range Rover

ERR4278LR - Throttle Potentiometer

- €230,00
€230,00
€230,00 - €230,00
€230,00
Genuine Part
Genuine: Original manufacturer part. This product is the original part designed and produced by the vehicle manufacturer.
Throttle Position Sensor (Potentiometer) for V8 petrol engines with Electronic Fuel Injection (EFI).

Mounts on the throttle body and signals throttle plate position to the engine management ECU. The ECU uses this signal to calculate fuelling demand across the operating range. Replace when the signal is erratic or the sensor is mechanically worn, which can cause hesitation, erratic idle, or poor throttle response.
Vehicle Model Land Rover Defender up to 2016
Land Rover Discovery 1 1989-1998 (L318)
Range Rover Classic 1994-2001 (P38)
Fitment Notes DEFENDER 1987-2006 — 4.0L V8 EFI Petrol
DISCOVERY 1 1989-1998 — 3.9/4.0L V8 Petrol EFI, North American spec (CDN/MEX/USA), VIN FA393361 to TA163100
RANGE ROVER P38 1994-2001 — 4.0L and 4.6L V8 EFI Petrol
Alternative Codes
ERR4278ERR4278LR

In stock 1 unit
1 · Gouda 0 · Drachten
Express delivery available

When will my order arrive?
  • Order before 15:00 (Mon–Fri): same-day dispatch for in-stock items.
  • UPS Express (order before 14:00): dispatched today, delivered tomorrow where available.
  • Netherlands / Belgium / Germany: 2–4 working days.
  • Other EU countries + UK: 4–8 working days.
  • Outside EU/UK: delivery times vary — contact us for an estimate.

Items may ship from multiple warehouses at no extra cost.

Job kits containing this part

This part is included in 0 job kit(s) below. Pick the kit that matches your vehicle and job, then add what you need.

Frequently asked questions

What does the Throttle Potentiometer do?
The Throttle Potentiometer, or throttle position sensor, mounts on the throttle body of V8 EFI petrol engines and signals throttle plate position to the engine management ECU. The ECU uses that signal to calculate fuelling demand. It's fitted to the Defender, Discovery 1 and Range Rover P38 V8 EFI.
What are the signs the throttle potentiometer needs replacing?
Common signs include hesitation, erratic idle and poor throttle response on the V8 EFI engine. These typically appear when the sensor's signal becomes erratic or the internal track wears. Left unreplaced, the ECU gets an unreliable throttle reading, which worsens driveability.
Does this fit my Discovery 1?
This Throttle Potentiometer fits the Discovery 1 (1989-1998) in North American spec (Canada, Mexico, USA) V8 EFI, within VIN range FA393361 to TA163100. It also fits the Defender and Range Rover P38 V8 EFI petrol, so check your VIN for Discovery 1.
Is ERR4278LR the same part as ERR4278?
Yes, ERR4278LR is the branded equivalent of the genuine Land Rover ERR4278 Throttle Potentiometer. Both cover the same V8 EFI throttle position sensor for the Defender, Discovery 1 and Range Rover P38, so either number fits the same application.

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