P2135
Throttle/Pedal Position Sensor Correlation Error
The PCM is seeing pedal and throttle signals that no longer track each other correctly. That usually points to a throttle-body fault, pedal-sensor fault, wiring problem, or a sticky throttle plate. It can put the vehicle into reduced-power mode, so the key diagnostic move is to compare both APP signals and both throttle-position signals before replacing parts.
- SEV
- 4/5
- DRIVE
- CAUTION
- DIY
- $20–$250
- SHOP
- $150–$700
Quick answer
AI-CITATION READYWhat it means
Can you drive with it?
Most common causes
- Throttle body throttle position sensor failure or internal throttle body fault
- Accelerator pedal position (APP) sensor assembly failure
- Wiring damage, corrosion, loose connector, or poor ground in the throttle or pedal sensor circuits
Typical repair cost
DIY usually runs $20–$250. Typical shop repair lands around $150–$700, depending on the root cause.
01 / Definition
P2135 indicates the powertrain control module has detected a mismatch between the throttle position sensor signals, often between TPS1 and TPS2, or related accelerator pedal position inputs depending on the vehicle design. The PCM expects these signals to track each other within a specific range; when they do not, it sets the code and may reduce engine power for safety.
02 / Drive status
With caution. The vehicle may lose power, hesitate, or go into reduced-power mode. Short, careful driving may be possible, but it is not safe to ignore the problem or drive normally if performance is unstable.
03 / Symptoms
- Check Engine Light
- Reduced engine power or limp mode
- Poor throttle response
- Hesitation or surging
- Rough or unstable idle
- Stalling
- Limited acceleration
- Possible traction control or electronic throttle warnings
04 / Causes
| 1 | Throttle body throttle position sensor failure or internal throttle body fault | high |
|---|---|---|
| 2 | Accelerator pedal position (APP) sensor assembly failure | high |
| 3 | Wiring damage, corrosion, loose connector, or poor ground in the throttle or pedal sensor circuits | high |
| 4 | Contaminated or sticking electronic throttle body causing signal mismatch | medium |
| 5 | PCM software issue, PCM fault, or failed sensor reference signal from PCM | low |
05 / Diagnostic sequence
- 01Scan for all stored and pending codes, including throttle, pedal, and PCM-related codes.
- 02Inspect the throttle body connector, APP connector, and related wiring for looseness, corrosion, damage, or water intrusion.
- 03Check live data for APP and throttle position sensor values and compare both pedal signals and both throttle-position signals for smooth, matching changes so you can see which pair drifts first.
- 04Verify 5-volt reference, ground, and signal voltage at the throttle body and accelerator pedal sensors.
- 05Look for throttle body carbon buildup or binding that could affect the sensor readings or plate movement.
- 06Clear codes and perform a relearn or idle/throttle adaptation procedure if required by the vehicle.
- 07If wiring and sensors test good, check for PCM software updates or perform deeper PCM circuit testing.
06 / Repairs
| 1 | Clean and secure throttle body and sensor connectors; repair any damaged wiring or grounds. | $20–$150 |
|---|---|---|
| 2 | Replace the throttle body assembly if the throttle position sensors are integrated and faulty. | $150–$500 |
| 3 | Replace the accelerator pedal position sensor assembly if readings are erratic or out of range. | $100–$300 |
| 4 | Perform throttle body relearn or PCM adaptation procedure after repairs. | $0–$100 |
| 5 | Update or replace the PCM only after all sensor and wiring checks confirm the module is the source of the fault. | $300–$900 |
MFG / Manufacturer notes
These supplements add make-specific diagnostic framing. Pages without full matrix backing or lane approval stay guarded and canonicalize back here until they are explicitly approved for indexing.
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Audi P2135
Expansion-candidate noindex child page
07 / Related codes
08 / FAQ
Can a dirty throttle body cause P2135?
Yes. Carbon buildup or a sticking throttle plate can contribute to mismatched sensor readings and trigger the code.
Is P2135 usually a pedal sensor or throttle body problem?
Most often it is the throttle body or accelerator pedal sensor assembly, but wiring faults are also very common.
Will clearing the code fix P2135?
Usually no. The code will return if the underlying sensor, wiring, or throttle problem is still present.
Why does P2135 often appear with P2101, P2111, or P2112?
Because the PCM is watching the whole electronic throttle system together. If the throttle plate sticks open or closed, or the actuator cannot follow commands, the throttle and pedal signals can stop agreeing and trigger a correlation code too.
09 / Source and method
- DATA BASIS
- OBD-II REFERENCE + OBD2.HELP
- METHOD
- STATIC VALIDATION
- SAFETY
- INFORMATIONAL
This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.
Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.
Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.