P0229
Fix within a few daysThe engine computer detects an intermittent problem with the 'C' circuit of your throttle position sensor or accelerator pedal position sensor.
Code P0229 means your throttle or pedal position sensor 'C' circuit has an intermittent fault. Common causes: Wiring issues (45%), APP sensor (35%), TPS (15%). Drivability: Limit driving, fix within a few days. Repair cost: $50-$250 DIY, $150-$450 professional.
Can I Drive With P0229?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy traffic. Be prepared for sudden changes in vehicle speed.
Stop driving immediately if: Flashing CEL, engine stalls repeatedly, vehicle accelerates on its own, or you experience significant power loss.
Symptoms of P0229
- 1Check Engine Light is on
- 2Engine hesitation or stumbling during acceleration
- 3Reduced engine power (limp mode)
- 4Engine stalls at idle or low speeds
- 5Inconsistent throttle response
- 6Vehicle accelerates on its own or does not accelerate when pedal is pressed
Common Causes of P0229
Parts most likely causing this code, ranked by probability
Loose, corroded, or damaged wiring and connectors to the accelerator pedal position sensor or throttle position sensor cause intermittent signal loss.
45% of P0229 cases are fixed by repairing wiring or connectors
An internal fault within the APP sensor causes an intermittent signal to the engine computer, leading to incorrect throttle commands.
35% of P0229 cases are fixed by replacing the APP sensor
An intermittent internal fault in the TPS sends incorrect throttle plate position data to the engine computer.
15% of P0229 cases are fixed by replacing the TPS
A rare internal fault within the PCM causes it to misinterpret or incorrectly process the sensor's signal.
5% of P0229 cases are fixed by replacing or reprogramming the PCM
Check These First (Before Buying Parts)
- Visually inspect the accelerator pedal assembly for any obstructions or damage that might prevent smooth operation.
- Check the electrical connectors at both the accelerator pedal position sensor and the throttle body for any signs of corrosion, bent pins, or loose connections. Disconnect and reconnect them to ensure a solid connection.
How to Diagnose P0229
- 1Visually inspect the wiring and connectors for the accelerator pedal position sensor and throttle position sensor for damage, corrosion, or looseness.
- 2Use a multimeter to test the resistance and voltage output of the APP sensor and TPS while slowly moving the pedal/throttle plate through its full range, looking for intermittent drops or spikes.
- 3Perform a 'wiggle test' on the wiring harnesses and connectors while monitoring live data from the APP and TPS sensors with a scan tool to identify intermittent connections.
- 4Check for Technical Service Bulletins (TSBs) related to P0229 for your specific vehicle make and model, as manufacturers sometimes have known issues.
P0229 on Popular Vehicles
Ford F-150
2004-2024Ford F-150s are known to have issues with the accelerator pedal position sensor (often integrated into the pedal assembly) and its wiring harness, leading to intermittent throttle response problems.
70% fixed by replacing APP sensor or repairing wiring
Toyota Camry
2007-2024Toyota Camry models can experience P0229 due to intermittent faults in the throttle body's internal TPS or wiring issues near the throttle body or accelerator pedal.
60% fixed by replacing TPS or repairing wiring
Honda Accord
2003-2024Honda Accord vehicles with P0229 often have issues with the accelerator pedal position sensor or corrosion in the electrical connectors leading to the sensor or throttle body.
65% fixed by replacing APP sensor or repairing wiring
Frequently Asked Questions
What does P0229 mean?
P0229 indicates that your vehicle's engine computer has detected an intermittent electrical problem with the 'C' circuit of either the accelerator pedal position sensor or the throttle position sensor. This means the signal from the sensor is not consistent.
Can I drive with P0229?
Limit driving, fix within a few days. This code directly impacts your vehicle's ability to accelerate and maintain speed safely. You risk sudden loss of power or unintended acceleration, which is dangerous.
Will P0229 clear itself?
No, P0229 will not clear itself. An intermittent electrical fault requires diagnosis and repair. The engine computer stores the code until the fault is resolved and the system passes its self-test.
How do I fix P0229 myself?
Start by inspecting all wiring and connectors to the accelerator pedal position sensor and throttle body for damage or corrosion. If wiring is good, use a multimeter to test the APP sensor and TPS for smooth voltage changes. Replace the faulty sensor if testing confirms an issue.
How much does it cost to fix P0229?
DIY repair costs range from $50 for a wiring repair to $250 for a new accelerator pedal position sensor. Professional shop costs range from $150 to $450, including diagnosis and parts.
P0229 keeps coming back - why?
P0229 keeps coming back because the underlying intermittent fault is still present. This often points to a subtle wiring issue, a faulty sensor that only acts up under specific conditions (like temperature or vibration), or a rare PCM problem that was not initially identified.
Will P0229 fail emissions/smog test?
Yes, P0229 will cause your vehicle to fail an emissions or smog test. The Check Engine Light is on, which is an automatic failure in states with emissions inspections.
What's the difference between P0229 and P0220?
P0229 specifically indicates an *intermittent* fault in the 'C' circuit of the throttle/pedal position sensor. P0220 indicates a general electrical fault in the 'B' circuit of the same sensor, which could be a constant open, short, or range/performance issue, not necessarily intermittent.
P0229 on Ford F-150?
On Ford F-150s, P0229 often points to issues with the accelerator pedal position sensor or its wiring. These trucks can experience wear in the pedal assembly or corrosion in the harness connectors, leading to intermittent signal problems.
Questions to Ask Your Mechanic
Did you check the live data from both the accelerator pedal position sensor and the throttle position sensor for intermittent drops or spikes?
Good answer: Yes, I monitored both sensors with a scan tool and performed a wiggle test on the wiring. I saw the voltage drop out intermittently on the APP sensor circuit C when I wiggled the connector.
What were the resistance readings for the APP sensor and TPS through their full range of motion?
Good answer: I tested the resistance on both sensors. The TPS showed a smooth, consistent change, but the APP sensor had a momentary open circuit at about 70% pedal travel.
Repair Cost Estimate
DIY Repair
Parts only
$50-$250
Shop Repair
Parts + labor
$150-$450
Save $100-$200 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate - requires a good understanding of electrical testing with a multimeter and a scan tool to monitor live data. Basic hand tools are also necessary.
Cost of Waiting
Ignoring P0229 leads to unpredictable throttle response, which is a serious safety hazard. You risk sudden loss of power or unintended acceleration. Continued driving with an intermittent fault can also cause the engine to run lean or rich, potentially damaging your catalytic converter ($800-$2,500 repair).
While You're In There...
If you are removing the throttle body to inspect or replace the TPS, replacing the gasket prevents vacuum leaks and ensures a proper seal.
Applying dielectric grease to electrical connectors (APP, TPS) helps prevent corrosion and ensures a good electrical connection, especially if you find signs of moisture.
Tools You'll Need
- OBD-II scan tool with live data capability
- Digital multimeter
- Basic hand tools (screwdrivers, wrenches, sockets)
- Wire stripper/crimper (if wiring repair is needed)
P0229 is a common electrical fault that mechanics see regularly. Pinpointing the intermittent issue takes patience, but once identified, the repair is straightforward and your vehicle will respond predictably again.
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Your Next Steps
Step 1: Perform a thorough visual inspection of all wiring and connectors for the accelerator pedal position sensor and the throttle body. Look for chafing, cuts, corrosion, or loose pins.
Step 2: If the visual inspection does not reveal the issue, use an OBD-II scan tool to monitor live data from both the APP and TPS sensors. Watch for erratic voltage readings or sudden drops while slowly pressing the pedal and wiggling the wiring.
Step 3: If live data points to a specific sensor, test that sensor directly with a multimeter. If the sensor tests good, the issue is likely wiring. If the sensor fails, replace it. Parts you'll likely need: Accelerator Pedal Position Sensor or Throttle Position Sensor.