P2135: Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation

P2135 compares the two position tracks of the electronic throttle, A and B, and sets when they no longer describe the same plate angle. GM's 2006-2007 tables allow a 7 % offset at closed throttle rising to 10 % at full opening and count failures every 12.5 ms until 19 of 39 have failed. Ford flags more than 7 degrees of disagreement; its 2012 and 2020-2023 summaries show only the wrench lamp, the 2024 summary also the MIL. Mitsubishi lists P2135 for the 2022 Outlander as a one-trip MIL code. Nissan bulletin NTB21-080 cures P2135 on the 2020-2021 Frontier without driveability complaints by ECM reprogramming. Mercedes traced it on AMG M177 V8s to high resistance in the throttle actuator pins. The ECU then limits throttle opening.

Symptoms

• Engine warning lamp or wrench lamp on
• Reduced engine power, limited throttle opening
• Rough or raised idle

Most likely causes

• Worn or contaminated position tracks in the throttle body
• Raised contact resistance or corrosion at the throttle connector
• ECM calibration prone to false detection (update available on some models)
• Fault on the shared 5 V reference or ground of both tracks

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pedal and throttle connectors
2. Compare both signals at the same time in live data and check any recent installation work.
3. Use live data to confirm that both sensors rise smoothly and consistently
4. Clean the throttle if it has carbon buildup
5. Run the relearn procedure with the scanner if the manufacturer requires it
6. Replace the part identified by the diagnosis

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P2135 means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 1: Air and fuel
• 35: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2135?

Do not keep driving more than necessary: the usual result is limp mode with an abrupt loss of power. Get off highways and take the car to a repair shop at low speed, or call a tow truck if it does not respond.

What causes code P2135?

The most common causes are: worn or contaminated position tracks in the throttle body; raised contact resistance or corrosion at the throttle connector; eCM calibration prone to false detection (update available on some models).

Related codes

• P2136Throttle/Pedal Position Sensor/Switch A/C Voltage Correlation
• P2137Throttle/Pedal Position Sensor/Switch B/C Voltage Correlation
• P0121Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance
• P0221Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance
• P0122Throttle/Pedal Position Sensor/Switch A Circuit Low
• P0222Throttle/Pedal Position Sensor/Switch B Circuit Low

Sources

• gsi.ext.gm.com: 07 GRP12 All Engines
• fordservicecontent.com: OBDSM2400OUTPUT 16Jul2024 WSM final V2 MCS7001
• static.nhtsa.gov: MC 10202255 0001
• static.nhtsa.gov: MC 10237505 0001

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.