P0229🔧 Throttle position sensor (TPS) / accelerator pedal position sensor, circuit CStop and fix promptly

P0229: Throttle/Pedal Position Sensor C Circuit Intermittent (Meaning, Causes, Fixes)

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0229 means

Many vehicles use more than one position sensor circuit to tell the engine computer (PCM) how far the throttle is open or how far the accelerator pedal is pressed; "C" refers to one specific circuit, and which physical sensor it is varies by vehicle. The two sources describe the code a little differently. OBD-Codes.com calls it "Throttle Position Sensor/Switch C Circuit Intermittent" and focuses on the throttle position sensor (TPS) on the throttle body: a potentiometer on a 5-volt reference circuit whose voltage changes as the throttle opens, which the PCM uses to calculate fuel delivery and ignition timing and to monitor air flow, oxygen content, EGR and engine load. It says the code sets when the PCM sees a certain number of intermittent or erratic signals from the sensor over a set period, under set conditions. RepairPal uses the standard name "Throttle/Pedal Position Sensor/Switch C Circuit Intermittent" and includes the accelerator pedal position sensor, which is part of the pedal assembly, saying the code sets when the PCM detects a problem with the sensor or its circuit. It is a generic code, and OBD-Codes.com mentions Dodge, Chrysler, Hyundai, Jeep and Mazda as examples. Related codes in the same family are P0225 (C circuit), P0226 (C range/performance), P0227 (C circuit low) and P0228 (C circuit high); P0220 to P0224 are the matching B-circuit codes.

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed promptly. RepairPal rates P0229 Urgent and says the engine computer may limit the car to about 20 mph or less (limp home mode). OBD-Codes.com says the code should be addressed with some degree of urgency because the throttle position sensor plays an important role in how the engine drives, and lists hesitation on acceleration among the symptoms. Avoid highway or heavy-traffic driving until it's checked, since the car may hesitate or lose power when you need it.

Common symptoms

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

  1. Faulty throttle position sensor (OBD-Codes.com also lists a misadjusted sensor) (OBD-Codes.com, RepairPal)
  2. Faulty accelerator pedal position sensor assembly (RepairPal only)
  3. Open or shorted wiring or loose connectors in the C sensor circuit (OBD-Codes.com, RepairPal)
  4. Binding or damaged throttle plate, including carbon build-up (OBD-Codes.com)
  5. Faulty engine computer (PCM) or a PCM programming error (OBD-Codes.com, RepairPal)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

  1. Check for technical service bulletins (TSBs) for your vehicle first; OBD-Codes.com says they are especially helpful for intermittent faults.
  2. Inspect the wiring and connectors at the throttle body and accelerator pedal for damage, looseness or corrosion (OBD-Codes.com).
  3. Look at the throttle plate for carbon build-up or damage and make sure it moves freely (OBD-Codes.com).
  4. Read and write down all stored codes and freeze frame data, clear the codes and test-drive. OBD-Codes.com notes that if the code doesn't come back right away, an intermittent fault may need to get worse before it can be pinned down.
  5. Watch the throttle position reading on a scan tool's live data while slowly opening and closing the throttle, looking for glitches or dropouts (OBD-Codes.com).
  6. With a multimeter on the sensor's signal and ground wires, slowly move the throttle from closed to wide open. OBD-Codes.com says voltage typically runs from about 0.5 volts closed to 4.5 volts wide open, and any glitch points to a bad or misadjusted sensor. Check your service manual for your vehicle's values.

Typical fixes

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

  • The car goes into limp mode or hesitates badly when you accelerate
  • You can't tell whether circuit C is on the throttle body or the accelerator pedal on your vehicle
  • The code keeps coming back after a new sensor and you don't have the adjustment specs
  • You don't have a scan tool or multimeter to catch an intermittent signal
  • Several throttle or pedal position codes are set at once

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0229?

Only carefully and not for long. RepairPal rates it Urgent and says the car may be limited to about 20 mph or less, and OBD-Codes.com lists hesitation on acceleration, so get it diagnosed promptly.

What does intermittent mean in P0229?

It means the engine computer saw the C sensor signal drop out or become erratic on and off rather than staying high or low. OBD-Codes.com says the code sets after a certain number of these glitches over a set period, which is why it can be hard to reproduce.

Is P0229 the throttle sensor or the gas pedal sensor?

It depends on the vehicle. RepairPal's definition covers both the throttle position sensor and the accelerator pedal position sensor, while OBD-Codes.com's article focuses on the throttle position sensor. Your service manual shows which sensor uses circuit C.

How much does it cost to fix P0229?

Neither source gives a repair cost for P0229. It can be as simple as fixing a loose connector or as involved as replacing a throttle body or pedal assembly, so diagnose it first.

Sources

  1. OBD-Codes.com: P0229 Throttle Position Sensor/Switch C Circuit Intermittent
  2. RepairPal: P0229 Throttle/Pedal Position Sensor/Switch C Circuit Intermittent (rated Urgent)

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.