How to Fix Fault Code P2135?

What is the fault code P2135? How do I fix the Throttle position sensor A and B Sensor signal mismatch (Correlation error) fault? What is the cause of fault code P2135? What are the symptoms and solutions to fault code P2135?

What does the P2135 Fault Code mean?

P2135 is the diagnostic fault code for ‘Throttle/Accelerator Pedal Position Sensor/Switch A/B Voltage Correlation‘. This fault code is generated when the vehicle computer (ECU/PCM), detects a problem with the accelerator or throttle pedal position sensor.
The throttle body is the cause of a decrease in engine performance, stuttering, stalling, or stuttering when you are at low revs. If you have these symptoms and receive a P2135 code, this indicates that there is a problem. You will have difficulty driving until the problem is resolved.

What Do Throttle Position (TP) and Throttle Pedal Position Sensors Do?

The 1990s saw the introduction of ‘Drive by Wire,’ a throttle control system. In order to control emissions, fuel efficiency, traction control and stability, cruise control and gearbox response, automotive manufacturers began installing ‘Drive by Wire’ throttle control technology in the 1990s. The vehicle’s throttle was previously controlled by a cable that ran between the accelerator and the throttle. The throttle position sensor was installed opposite the throttle connection. The TPS converts movement and position of throttle valves into voltage signals. This signal is sent by the engine control computer to create an engine management strategy. The new “Electronic Throttle Control” technology is made up of an accelerator pedal sensor, an electronically-controlled throttle body, two embedded sensors to determine correlation factors and an engine management system.
The throttle body is the part of your vehicle that connects these two sensors. The throttle valve is what allows air into the engine. The more you press on the accelerator pedal, it will open more and allow more air into the engine. The ECU can calculate the amount of air that enters the engine by using the throttle position sensors.

The throttle pedal position sensor, on the contrary, is responsible for monitoring how much fuel enters the engine, based on your pressing the accelerator pedal.

What triggers fault code P2135?

In normal conditions, both sensors’ signals should be in sync. Both pedal position sensors should show similar data. Fault code P2135 will be triggered if these data are not correlated, and data from other sensors is sent to the ECU. If, for example, one sensor reports the throttle as being half-open and the other reads it as fully or partially open, then there is a logical mistake. When the accelerator pedal is depressed 60%, then the throttle plate must also be opened 60%. These two sensors should send the same signals to the ECU. The system will be working properly if both voltages are equal. P2135 is set if they are different by more than two seconds. This indicates a fault in the system. This code may be accompanied by other fault codes to help further pinpoint the problem. A loss of throttle control can be dangerous.

Is Fault Code P2135 Important?

The fault code P2135 can cause misfiring. You should not drive your vehicle if this fault code is still present.

What are the typical symptoms of fault code P2135?

• Low engine power. You may be in ‘Limp mode / Engine protection mode’.
• When pressing the accelerator, there may be hesitation, interruption or difficulty in accelerating.
• Failure to start after stopping.
• RPM fluctuations without pressing the accelerator pedal.
• The engine revs higher than normal (RPM/minute).
• The “Check Engine” warning light will illuminate.

Causes of Fault Code P2135

• Malfunctions on throttle body or the throttle pedal position sensor can cause problems.
• The throttle body can cause problems.
• Terminal connectors that are broken or worn out
• Cable problems: Faulty or damaged cables
• PCM/ECU related issues
• The use of dielectric grease with zero or very low conductivity

How to Diagnose Fault Code P2135?

Use an OBD2 scanner to read both TP sensor signals when your vehicle is stationary. Sensor 1 and Sensor 2 readings can be different. This is normal. You need to see if the acceleration rates are related. Slowly press the accelerator while the vehicle is idle and watch to see if the voltage outputs are equal. If the voltage outputs do not increase equally, or if you notice a significant increase or decrease on one of the sensors, then the code is likely to be triggered by this sensor.
Check the cables underneath the bonnet while you continue to monitor the data. Check the signal from the sensor by moving the cables. During this time, have someone keep pressing the accelerator.

Remove the connectors for the TP sensors and inspect them for corrosion. Check the cables that connect the sensors to the vehicle computer and check for wear and short circuits.

The problem can be resolved by cleaning the throttle body frequently. You will need an electronic cleaner aerosol and a brush for this.

If this does not work, you will need to replace the sensor.

Note: Fault codes P2135, P2136, and P2137 are identical. All fault codes are diagnosed using the same diagnostic method.

Frequently Asked Questions about P2135