OBD-II Code P2135 – Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation: Explanation and Repair
As a professional mechanic, I have come across various OBD-II codes throughout my career, and one of the most common codes that vehicle owners complain about is Code P2135 – Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation. But what does this code mean, and how can it be fixed? This article will comprehensively explain what OBD-II Code P2135 means, its symptoms, and how to repair it.
What is OBD-II Code P2135?
OBD stands for On Board Diagnostics, which is a standard system used in vehicles to detect problems and issues. OBD-II Code P2135, on the other hand, is an issue detected by the OBD system, specifically in the Throttle/Pedal Position Sensor/Switch A/B. The code indicates that the voltage readings from the Throttle Position Sensor (TPS) and the Accelerator Pedal Position Sensor (APPS) have gone out of range, creating a waveform mismatch.
The TPS and APPS perform separate but complementary functions in the vehicle’s powertrain control module (PCM). The throttle position sensor is mounted on the throttle body butterfly valve shaft and is responsible for determining the position of the throttle valve and calculating the load put on the engine. The APPS, on the other hand, is located on the accelerator pedal and determines the position of the pedal when pressed.
When the PCM detects that the voltage readings from both sensors are not matching or are out of range, Code P2135 is triggered. This mismatch in signals can cause the powertrain to misbehave, leading to a variety of driveability issues.
Symptoms of OBD-II Code P2135
Some of the commonly reported symptoms associated with OBD-II Code P2135 include:
1. Stalling or idle surging: The vehicle may stall altogether or idle roughly with its rpms surging erratically.
2. Limited throttle control: You may experience limited power and control of the throttle; for instance, the throttle may not respond promptly or may not respond at all.
3. Engine light illuminates: The check engine light (CEL) on your dashboard may turn on steadily or flash on and off fast.
4. Reduced power mode: Some vehicles may go into a reduced power mode as a safety feature to prevent further damage to the powertrain.
5. Transmission shifting problems: You may notice your car may not shift gears properly when accelerating or may experience transmission slippage.
How to Repair OBD-II Code P2135?
To repair the problem caused by OBD-II Code P2135, your mechanic must run a diagnostic test to establish the underlying issue. The most common causes of this problem include:
1. Dirty Throttle Body: If the plate of the throttle body is dirty, it can interfere with the sensor’s readings, triggering Code P2135. In such a case, the throttle body is removed, cleaned and reinstalled to ensure it’s clean and that the sensors’ signals match.
2. Faulty Throttle Position Sensor: A failed throttle position sensor can cause voltage readings to go out of range. In such a case, replacing the sensor with a new one will fix the issue.
3. Damaged Accelerator Pedal Position Sensor: Sometimes, the issue may lie in the pedal sensor. The pedal position sensor may have developed a mechanical or electrical defect, causing the voltage to go out of range and triggering code P2135. In such cases, replacing the APPS would solve the problem.
4. Damaged Wiring: Loose or damaged wiring could also cause the voltage reading to go out of range, triggering code P2135. Your mechanic would have to inspect the wiring and repair any loose, damaged or corroded connections.
5. Failure of the Powertrain Control Module: In rare cases, the PCM could malfunction, leading to Code P2135. In such a case, replacing the PCM is the only viable option.
Frequently Asked Questions (FAQs)
1. Can I drive my car with Code P2135?
You can still drive with Code P2135, but it is advisable to seek a mechanic’s services as soon as possible. Driving with the code may have adverse effects on your vehicle’s performance and overall safety.
2. How much does it cost to fix code P2135?
The cost of fixing a code P2135 varies depending on the underlying cause of the problem. Fixing a damaged wiring system may cost a few dollars, while replacing some sensors may require more money.
3. How do you clear Code P2135?
Clearing code P2135 requires a professional OBD-II scanner or code reader that can reset the diagnostic codes. Once the underlying problem is fixed, the scanner can clear the code.
4. Can Code P2135 trigger other codes?
Yes, code P2135 can trigger other codes in your car as it affects the powertrain, including the transmission, fuel system, and ignition control system.
5. How can I prevent Code P2135 from recurring?
The easiest way to avoid recurring code P2135 is by maintaining your vehicle regularly through oil changes, air filter changes, and regular tune-ups. Additionally, ensuring that the terminals of the throttle position and accelerator pedal position sensors are clean and that the sensor wiring connections are secure will go a long way in avoiding recurring codes.
In conclusion,
Code P2135 can be frustrating and, if left unchecked, can cause some severe engine issues. Prompt diagnosis and repair of the issue are crucial to solving this problem. If you experience any of the symptoms associated with Code P2135, it is vital to contact a certified mechanic to diagnose your vehicle accurately.