P0123

Throttle/Pedal Position Sensor/Switch A Circuit High

Car Fault Codes 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 2,500

What it means

The engine computer has seen the signal voltage from throttle or pedal position sensor A above the highest acceptable level. The cause is usually a lost ground or the signal wire shorted to the reference voltage, and the computer normally enters limp mode.

Symptoms4

Check engine light on, possibly with the electronic throttle warning light.
Limp mode with a severe loss of power.
High or unstable idle on some cars.
Abnormal response to the accelerator.

Possible causes5

Open ground wire to the sensor.
Signal wire shorted to the reference voltage or another voltage source.
Corroded connector or moisture inside it.
Failed sensor or the throttle body it is built into.
Engine computer fault (rare).

How to diagnose5

Watch the sensor signal on a scan tool with the throttle closed; a very high value without the throttle opening means an electrical fault.
Measure the ground at the sensor connector and confirm it is sound.
Check the signal wire for a short to the reference voltage.
Inspect the connector for moisture or corrosion.
If the wiring is good, watch the signal while moving the throttle to confirm the sensor has failed.

How to fix5

Repair the open ground wire.
Repair the short in the harness.
Clean, dry and reconnect the connector.
Replace the sensor, throttle body or pedal assembly depending on the design.
Run the relearn procedure if required, then clear the codes and road test.

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.

The cost is low for a ground or shorted wire repair, and reaches the upper end when the electronic throttle body is replaced.

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

Can the car accelerate on its own because of this code?

Modern systems monitor two sensors and enter limp mode on any disagreement to prevent that, but any abnormal pedal behavior calls for stopping and checking right away.

Can I drive with this code?

Carefully and only a short distance to a workshop, because a sudden loss of power can be dangerous on highways.

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.

Report a mistake

Spotted something inaccurate? Tell us and we will review and correct it.