Throttle valve spring itself has weakened, broken, or become dislodged from its seat; Throttle body mechanical binding or carbon buildup preventing the plate from returning freely; Faulty throttle position sensor (TPS) or accelerator pedal position sensor sending implausible signals; Damaged or corroded wiring and connectors between the throttle body and the ECM; Failed electronic throttle actuator motor or its internal feedback circuit; ECM software glitch or internal driver fault requiring reflash or replacement; Contaminated throttle body from oil vapors or dirt causing excessive spring load

DTC codes / Jaguar codes / P1250

P1250 · JaguarThrottle Valve Spring

Q: What does code P1250 mean?

Throttle Valve Spring. P1250 on a Jaguar indicates that the engine control module (ECM) has detected a fault in the throttle valve spring circuit, which is responsible for returning the throttle plate to its default position when the accelerator is released. The ECM monitors the spring's electrical circuit and compares expected throttle position feedback against actual movement, and it sets this code when the spring's resistance or response falls outside the programmed limits.

P1250 on a Jaguar indicates that the engine control module (ECM) has detected a fault in the throttle valve spring circuit, which is responsible for returning the throttle plate to its default position when the accelerator is released. The ECM monitors the spring's electrical circuit and compares expected throttle position feedback against actual movement, and it sets this code when the spring's resistance or response falls outside the programmed limits.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Reduced engine power or limp-home mode with a sluggish throttle response
Throttle pedal feels different or returns more slowly than usual
Rough idle or stalling when coming to a stop
Inconsistent acceleration or hesitation during light throttle application
Electronic throttle control warning message displayed on the instrument cluster

Common causes, most likely first

Throttle valve spring itself has weakened, broken, or become dislodged from its seat
Throttle body mechanical binding or carbon buildup preventing the plate from returning freely
Faulty throttle position sensor (TPS) or accelerator pedal position sensor sending implausible signals
Damaged or corroded wiring and connectors between the throttle body and the ECM
Failed electronic throttle actuator motor or its internal feedback circuit
ECM software glitch or internal driver fault requiring reflash or replacement
Contaminated throttle body from oil vapors or dirt causing excessive spring load

How to diagnose and fix it

Connect a Jaguar-compatible scan tool and read all stored and pending codes, then record freeze-frame data for P1250
Visually inspect the throttle body, linkage, and spring for obvious damage, binding, or debris, and clean the throttle bore if carboned
Check the throttle valve spring's resistance and return action manually with the ignition off, comparing to factory specifications
Perform a guided diagnostic routine for the electronic throttle control system using dealer-level software to test the actuator and sensors
Inspect the wiring harness and connectors at the throttle body and ECM for chafing, corrosion, or loose pins, and repair as needed
If the spring or throttle body assembly is faulty, replace the throttle body with a matched unit and perform throttle adaptation relearn
Clear codes, road test the vehicle through several drive cycles, and verify P1250 does not return

Why P1250 is often a throttle body issue

A weak or broken throttle valve spring is frequently caused by normal fatigue over many heat cycles, but carbon buildup on the throttle plate can mimic spring failure by adding return resistance.
Technicians sometimes replace the throttle body only to find the real fault is a chafed wire in the harness near the throttle body connector, so always perform a wiggle test and voltage drop check before condemning parts.
On some Jaguar models, a low battery or voltage spike during engine start can set P1250 as a false code, so verify battery health and clear codes before deeper diagnosis.
The ECM may set P1250 alongside throttle position sensor codes like P0121 or P0221, and diagnosing only the spring can miss a failing sensor that is skewing the feedback signal.
After any throttle body replacement or repair, a throttle adaptation relearn with a capable scan tool is mandatory, or the ECM may continue to set P1250 due to learned values.

Can I keep driving with P1250?

You can usually drive the vehicle to a workshop, but expect reduced power and avoid aggressive acceleration or heavy loads until the fault is repaired. If the throttle response becomes erratic or the engine stalls repeatedly, stop driving and arrange a tow to prevent a safety hazard.

Tools that help

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Guidance is general and written for Jaguar vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.