Throttle/Pedal Position Sensor Correlation Error
The P2135 code indicates a correlation fault between the throttle position sensor (TPS) A and B signals, or between the accelerator pedal position sensor (APP) and the throttle position sensor. The PCM detects that the voltage readings from these sensors do not match within a specified range, often due to a faulty sensor, wiring issues, or a sticking throttle body.
01. Most Common Causes
- Faulty throttle position sensor (TPS)
- Faulty accelerator pedal position sensor (APP)
- Wiring or connector issues (corrosion, shorts, opens)
- Carbon buildup causing throttle plate sticking
- Faulty PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Reduced engine power (limp mode)
- Poor acceleration or hesitation
- Rough idle or stalling
- Unresponsive or erratic throttle
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect wiring and connectors for damage or corrosion.
Step 3: Test TPS and APP sensor voltages with a multimeter; compare to specs.
Step 4: Clean throttle body and check for carbon buildup.
Step 5: If sensors fail, replace and relearn throttle position if required.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The vehicle may enter limp mode, reducing power and increasing risk of accidents. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, but can be higher if the throttle body or PCM needs replacement.