The P1122 trouble code is a diagnostic trouble code (DTC) that indicates an issue with the throttle position sensor (TPS) circuit, specifically signaling an intermittent low voltage condition. This code is typically associated with vehicles equipped with electronic throttle control systems. When the powertrain control module (PCM) detects that the TPS is not providing a consistent voltage signal, it triggers the P1122 code. Understanding this code is essential for vehicle owners and DIY mechanics, as it can lead to performance issues and increased emissions if not addressed promptly.
| P1122 Code Meaning | P1122 Code Common Causes |
|---|---|
| Throttle Position Sensor Circuit Intermittent Low Voltage | Faulty throttle position sensor |
| Inconsistent voltage signal from TPS | Damaged wiring or connectors |
| Electric throttle control performance problem | Corroded electrical connections |
| Limp mode activation due to safety protocols | Low system voltage or battery issues |
| Potential issues with the PCM or ECU | Faulty accelerator pedal position sensor (APP) |
Symptoms of P1122 Code
When the P1122 code is triggered, drivers may experience several symptoms, including:
- Poor acceleration: The vehicle may struggle to gain speed due to limited throttle response.
- Limp mode: The engine may enter limp mode, restricting power and speed to prevent further damage.
- Check Engine Light: The illumination of the check engine light on the dashboard is a common indicator of trouble codes.
- Increased fuel consumption: An erratic throttle response can lead to inefficient fuel usage.
Technical Explanations
The throttle position sensor (TPS) is a critical component in modern vehicles, providing feedback to the PCM about the position of the throttle plate. The TPS operates as a variable resistor, changing its resistance based on the throttle position. This change in resistance alters the voltage signal sent to the PCM, which uses this information to adjust fuel injection and ignition timing accordingly.
The P1122 code indicates that the PCM has detected an intermittent low voltage signal from the TPS. This could stem from several issues:
- A faulty TPS that cannot provide a consistent voltage.
- Damaged wiring or corroded connectors disrupting the signal transmission.
- Low system voltage affecting sensor performance.
Step-by-Step Diagnosis
To diagnose and resolve the P1122 code, follow these steps:
- Scan for Codes: Use an OBD-II scanner to confirm that P1122 is present and check for any related codes.
- Visual Inspection: Inspect the wiring and connectors associated with the TPS for any visible damage, corrosion, or loose connections.
- Check Voltage at TPS:
- Disconnect the TPS connector.
- Using a multimeter, measure the voltage at the connector while turning the ignition on (but do not start the engine). You should see approximately 5 volts on one terminal.
- With someone pressing the accelerator pedal, observe if the voltage changes smoothly from idle to wide-open throttle (WOT).
- Test Resistance: If necessary, test the resistance of the TPS using an ohmmeter to ensure it varies correctly with throttle movement.
- Inspect Accelerator Pedal Position Sensor (APP): If applicable, check for faults in the APP as it can also affect throttle response.
- Check PCM Functionality: If all other components are functioning correctly, consider testing or reprogramming the PCM.
Solution Methods
Depending on your diagnosis, here are potential solutions:
- Replace Throttle Position Sensor: If testing indicates that the TPS is faulty, replacing it will often resolve P1122.
- Repair Wiring/Connectors: If damaged wiring or corroded connectors are found, repair or replace them as needed.
- Check Battery Voltage: Ensure that your vehicle’s battery is fully charged and that there are no issues with electrical connections.
- Professional Help: If you are unable to identify or resolve the issue, consult a professional mechanic who can perform advanced diagnostics.
Cost Estimates
The cost of repairs related to P1122 can vary widely based on your vehicle’s make and model:
- Throttle Position Sensor Replacement: $50 – $200 for parts; labor costs may add another $50 – $150 depending on local rates.
- Wiring Repairs: Costs can range from $20 for minor repairs to several hundred dollars if extensive wiring harness replacement is needed.
- Diagnostic Fees: If you take your vehicle to a mechanic for diagnosis, expect to pay between $75 – $150 for labor.
Warnings and Recommendations
- Stop Driving Immediately: If you experience significant performance issues or enter limp mode due to P1122, it’s crucial not to drive until repairs are made. Continuing to drive can lead to further damage.
- Use Quality Parts: Always opt for OEM or high-quality aftermarket parts when replacing components like sensors or wiring.
- Regular Maintenance: Regularly inspect your vehicle’s electrical systems and connections as part of routine maintenance to prevent issues like P1122 from arising.
Closing Paragraph
The P1122 trouble code signifies a serious issue with your vehicle’s throttle position sensor circuit that must be addressed promptly. By understanding its symptoms and causes and following proper diagnostic procedures, you can effectively troubleshoot and resolve this code. Whether you’re a DIY mechanic or seeking professional assistance, addressing this issue will help ensure your vehicle operates safely and efficiently.
Frequently Asked Questions About P1122
- What does error code P1122 mean?
P1122 indicates an intermittent low voltage signal from the throttle position sensor circuit. - Can I drive my car with a P1122 code?
It’s advisable not to drive your car if you see this code since it can lead to reduced power and performance. - How do I fix error code P1122?
Fixing P1122 typically involves checking and possibly replacing the throttle position sensor or repairing any damaged wiring. - What are common symptoms of P1122?
Common symptoms include poor acceleration, limp mode activation, increased fuel consumption, and illuminated check engine light. - Is it safe to clear error codes myself?
You can clear error codes using an OBD-II scanner; however, ensure underlying issues are resolved before doing so. - Can low battery voltage cause a P1122 code?
Yes, low battery voltage can affect sensor operation and potentially trigger a P1122 code. - How much does it cost to fix a P1122 code?
The cost can range from $50 for parts alone up to several hundred dollars depending on necessary repairs. - When should I seek professional help for a P1122 code?
If you’re unable to diagnose or fix the issue after basic troubleshooting, it’s best to consult a professional mechanic.