P1125

Accelerator Pedal Position (APP) System

Car Fault Codes Chevrolet Fuel & air

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 2 hours

Typical cost SAR 100 to 1,500

What it means

This is a Chevrolet (GM) manufacturer-specific code, and the same number can mean something different on other makes. The accelerator pedal on these systems has more than one sensor, and this code means the pedal system as a whole is no longer trusted, usually because more than one pedal sensor or circuit has a fault. The computer then severely limits engine power, and the engine may barely respond to the pedal.

Models covered: Chevrolet (GM) models with electronic throttle control, mainly around 1997–2006.

Symptoms4

Very weak pedal response, or the engine stays close to idle.
Reduced engine power message and check engine light.
Other pedal sensor codes usually stored with it.
An intermittent fault at a certain pedal position.

Possible causes5

A corroded or loose pedal assembly connector.
Failed sensors inside the pedal assembly.
A short on the 5-volt reference shared by the pedal and other sensors.
A damaged wire under the dashboard or at the firewall.
A fault in the throttle actuator control (TAC) module or engine computer (rare).

How to diagnose5

Read all codes; the individual pedal sensor codes show which circuit is affected.
Watch the pedal sensor readings on a scan tool while pressing slowly and confirm they change smoothly and in step.
Inspect the pedal connector and terminals for corrosion or looseness.
Measure reference and ground for each sensor and compare with the manufacturer specification.
If a short is suspected, unplug other sensors on the same reference circuit and see whether the voltage returns.

How to fix5

Clean and secure the pedal connector.
Repair the damaged wire or the short on the reference circuit.
Replace the complete pedal assembly if its sensors are confirmed faulty.
Perform any relearn the manufacturer requires.
Clear the codes, road test the response and confirm the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

A connector or wire repair is the low end, while a complete pedal assembly with relearn is the high end.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Why does the vehicle barely accelerate?

The computer cannot tell reliably how far the pedal is pressed, so it limits power to a minimum to prevent unintended acceleration.

Can one sensor inside the pedal be replaced?

On these models the sensors are built into the pedal assembly, so the fix is the complete assembly once the wiring is confirmed good.

Which generic codes are related?

Newer models set generic codes for each pedal sensor, such as P2122 and P2127, and P2138 when two pedal sensors disagree.

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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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