You’re stopped at a stoplight, waiting for the light to turn green. Once the light changes, you suddenly notice that no matter how hard you step on the gas, engine power is significantly reduced.
After you limp the vehicle home, you plug in your diagnostic tool and it reads P2135. What does this code mean and why are you experiencing these problems?
Read on to find out.
What Does the P2135 Code Mean?
Diagnostic trouble code (DTC) P2135 stands for “Throttle/Pedal Position Sensor/ Switch A/B Voltage Correlation.” This code appears when your car’s primary computer, which is often referred to as the powertrain control module (PCM), detects a problem with one of throttle and/or the pedal position sensors/switches.
The throttle position (TP) sensor is located on the throttle body. On the other hand, the accelerator pedal position (APP) sensor is usually part of the accelerator pedal assembly.
Most vehicles have what’s referred to as an electronic throttle actuator (TAC) system. With this design, instead of traditional throttle linkage, an electric motor operates the throttle blade in response to commands from the PCM. The latter calculates TAC operation primarily from the TP and APP sensor signals.
A typical TAC system has two TP sensors and two APP sensors for fail-safe reasons.
If the data between one of the sensor pairs (e.g, the two throttle position sensors) does not correlate, code P2135 is set. In most cases, the ECM will also force the vehicle into Reduced Power Mode.
What are the Possible Causes of the P2135 Code?
Error code P2135 can have a lot of potential causes. Below are just some of the possible issues that may have resulted in the P2135 code:
- Accelerator pedal position assembly failure
- TPS failure
- PCM issues (e.g., software is outdated)
- Circuit problems (e.g., damaged wires and poor connections)
What are the Common Symptoms of the P2135 Code?
You may notice one or more of the following symptoms when error code P2135 is set:
- Decreased engine performance
- Engine going into “limp home” (Reduced Power) mode
- Frequent stalling or sudden stopping
- Check engine light is on
How to Diagnose the P2135 Code
Because many issues can trigger the P2135 code, you may have a hard time pinpointing its exact cause. Use these detailed video references as a guide to help you diagnose the code properly:
How to Fix the P2135 Code
If you are not confident with your automotive know-how and DIY skills, let your mechanic take care of the issue. Otherwise, you may address the P2135 code yourself.
Identify what triggered the code, then figure out how to resolve it by doing your research on confirmed fixes that apply to your specific vehicle. You can also use these online auto repair resources and guides or get an ALLDATA subscription (for comprehensive factory repair information) in order to get more guidance.
Be sure to consult your owner’s manual before starting the repair process. What works for one vehicle might not work for another because different makes and models typically have their specific repair instructions. You don’t want to accidentally make the problem worse with an inappropriate fix.
When in doubt, contact your mechanic.
Other Notes About Code P2135
Other vehicle manufacturers will label this code differently, such as: “throttle position sensor circuit range/performance” on a Nissan Infiniti or “electronic throttle control system malfunction power management” on a Hyundai.