Carlexica

P0123: Throttle/Pedal Position Sensor/Switch A Circuit High

A generic powertrain (engine and transmission) trouble code, same meaning on every brand.

Fix now, drive carefully

Same as P0122 - limp mode likely, repair promptly.

$80 - $800
typical repair range
15
NHTSA complaints mention this code
123,000
median mileage when reported, mi

Symptoms

  • Limp mode, erratic idle
  • Unpredictable throttle response

Likely causes, most common first

  1. TPS signal shorted to voltage
  2. Harness damage
  3. Throttle body sensor failure

Read P0123 yourself before paying for diagnosis

A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.

What is going on and how it gets diagnosed

P0123 pegs the throttle signal high - to the computer that looks like a floored pedal it did not command, so it responds with heavy restrictions. The high-voltage variant tends to point at wiring more often than the sensor itself.

Inspect the harness where it flexes near the throttle body; years of engine rocking fatigue the copper. After any repair, complete the throttle relearn or the idle will hunt.

Repair options and cost

Wiring repair$80 - $250
Throttle body replacement$300 - $800

Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.

Owner reports mentioning P0123

“Check engine light came on. Had it diagnosed within 5 minutes. Code P0123 came up. That is the "Throttle/Pedal Position Sensor/Switch "A" Circuit High Input". Specific part # 5184349AF. It is built into the throttle body, so whole throttle body must be replaced. Vehicle only has 40,000 miles. Parts Dept at dealer told me they had several of these parts in stock. He was surprised. They only do that when they know there is a problem. It is a safety issue. It can fail and cause engine to quit. Jeep refuses to acknowledge an existing problem. It needs government investigation for safety. I can send picture of diagnosis printout if needed.”2019 Jeep Cherokee · Jul 2021
“Vehicle respond to a light acceleration request with sustain full throttle operation. The vehicle traveled in poor road conditions with full throttle operation. The only influence in course change was terrain and torque steering. After collision with a stone pillar code p0123 throttle high voltage was found.”2004 Dodge Neon · Feb 2016 · 150,000 mi
“Beginning december 2002, vehicle will unexpectedly lose power and lack accelerator response. Code p0123 active and present indicating problem in the throttle position sensor circuit. Sensor replaced and wiring inspected. Problem persists.”2001 Chevrolet S10 · Jan 2003 · 39,215 mi

Cars that report P0123 most often

Based on mentions of this code in NHTSA owner complaints.

2001 Chevrolet S101 mentions in complaints2019 Mercedes-Benz C 3001 mentions in complaints2003 Dodge Durango1 mentions in complaints2008 Nissan Altima1 mentions in complaints2006 Volkswagen Passat1 mentions in complaints2019 Jeep Cherokee1 mentions in complaints2009 Hyundai Azera1 mentions in complaints2004 Dodge Neon1 mentions in complaints2018 Jeep Cherokee1 mentions in complaints1997 Dodge Ram 15001 mentions in complaints2015 Dodge Dart1 mentions in complaints2018 Jeep Compass1 mentions in complaints

Frequently asked questions

Can I drive with P0123?

Same as P0122 - limp mode likely, repair promptly.

How much does it cost to fix P0123?

Typical US repair costs range from $80 for the simplest fix (wiring repair) to $800 in the worst case. The right number depends on which cause your car has - see the causes list.

Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.