Throttle/Pedal Position Sensor/Switch B Circuit High
What it means
The engine computer has detected that the B signal voltage from the throttle position sensor or accelerator pedal sensor is above its maximum allowed value. The usual cause is an open sensor ground or a signal wire shorted to a voltage source, so the computer rejects the signal and enters limp mode.
Related lights
Dashboard lights that may come on with this code.
Symptoms4
- Check engine light on with a reduced power message or light.
- Very weak acceleration.
- Abnormal idle speed.
- The fault may come and go with vibration or bumps.
Possible causes5
- Open sensor ground wire or a corroded ground terminal in the connector.
- Short between the B signal wire and the reference voltage wire or another voltage source.
- Moisture in the connector causing current leakage between terminals.
- Internal sensor failure.
- Engine computer fault (rare).
How to diagnose5
- Watch the B signal voltage on a scan tool; a reading near the full reference voltage suggests an open ground or a short to voltage.
- Measure the voltage drop on the ground wire between the sensor and the computer.
- Unplug the sensor and watch the signal; if it stays high, the wire is shorted to a voltage source.
- Inspect the connector for moisture or corrosion between terminals.
- Wiggle the wiring while watching to catch an intermittent fault.
How to fix5
- Clean and dry the connector or replace it.
- Repair the open or corroded ground wire.
- Separate the shorted wires and re-insulate and secure them.
- Replace the pedal sensor or the throttle body assembly depending on where the fault is, then perform the relearn.
- Clear the codes, then road test and confirm the code does not return.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
In the Saudi market: SAR 100–2,500 (≈ USD 27–667)
Our prices come from the Saudi market, converted at a fixed rate (SAR 3.75 per USD). Prices in your country may differ a lot, so we show the cost level.
The cost is low for a ground or connector repair, rises for a pedal sensor, and reaches the upper end when the electronic throttle body assembly 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
Why does an open ground cause high voltage?
The sensor works as a voltage divider, so when its ground side opens the signal rises toward the full reference voltage and the computer reads it as too high.
Is the sensor necessarily bad?
No. The cause is often in the wiring or connector, so test the ground and inspect the connector before replacing the sensor.
Can I drive with this code?
Only a short distance and with care, because power is limited in limp mode.
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