Fix P2135: Mechanic’s solutions that WORKED

The P2135: Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation code indicates a problem with the correlation of voltage signals from the throttle position sensor and the pedal position sensor. This issue can significantly affect the vehicle’s performance, potentially causing erratic throttle responses, stalling, or even preventing the vehicle from driving properly.

P2135 quick overview

Meaning	P2135: Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation
Is it serious?	Yes, it can be serious. It affects the vehicle’s throttle response and can lead to poor engine performance, stalling, or inability to drive the vehicle.
Possible causes	– Faulty Throttle Position Sensor (TPS) – Damaged or corroded wiring/connectors to the TPS – Issues with the throttle body – Faulty Engine Control Module (ECM)
How to diagnose?	Check for Additional Codes: Look for other diagnostic trouble codes that might be related to the throttle system. Inspect Wiring and Connectors: Examine the wiring and connectors leading to the TPS for damage or corrosion. Test Throttle Position Sensor: Using a multimeter, test the TPS to check if it’s within the specified range. Throttle Body Inspection: Check the throttle body for any physical damage or obstructions. ECM Software Update: Ensure the ECM has the latest software version. Check Vehicle’s Warranty: If applicable, verify if the issue is covered under the vehicle’s warranty.

How to fix P2135 – learn from mechanics

I looked into P2135 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Jaguar

Vehicle Information

• 2005 Jaguar Vanden Plas, 4.2L

Issue + Repair History

• MIL (Malfunction Indicator Lamp) on
• Fault Code: P2135 (TPS Sensor Correlation)
• Needed throttle body replacement due to a bad TPS

Other OBD2 Codes + Test Results

• No additional codes or test results mentioned

Suggestions from Community

• Check if programming is required for the new throttle body
• Clear fuel adaptions and codes post-repair
• Ensure battery is disconnected during installation
• Initialization of the system upon starting after installation

Final Fix

• Replaced the throttle body and disconnected the battery during installation
• No further issues, and the code did not return

Case #2: Cadillac

Vehicle Information

• 2009 Cadillac Escalade ESV Platinum, 6.2L

Issue + Repair History

• Hesitation, cuts out, stall, MIL lamp on
• Code P2135 (TP sensor voltage correlation between 1 & 2)
• Throttle sensor replaced

Other OBD2 Codes + Test Results

• No additional codes or test results mentioned

Suggestions from Community

• Check for a special policy for TPS replacement up to 120,000 miles through Cadillac
• Review TSB #11-06-04-007B related to MIL illumination and DTC P2135
• Scope TP sensor values to ensure they meet manufacturer specifications
• Consider replacing the throttle assembly
• Perform an ECM update after replacing TPS/cover

Final Fix

• Followed a TSB which entailed replacing the TPS and reflashing the ECM
• Service performed by the local dealer free of charge under a special policy covering up to 120,000 miles

Case #3: Nissan

Vehicle Information

• 2004 Nissan Sentra, 1.8L

Issue + Repair History

• Hesitation, MIL lamp on
• Code P2135 (TPS)
• Throttle body considered for replacement due to issues with TPS

Other OBD2 Codes + Test Results

• No other codes or test results mentioned

Suggestions from Community

• Check if the vehicle is still under warranty (5 years, 60,000 miles)
• Consider remanufactured throttle body units as a cost-effective solution
• The electrical TPS portion of the throttle body is likely faulty and might not be separately serviceable
• The throttle shaft seal might be worn or damaged, possibly due to induction cleaning

Final Fix

• Confirmed that the powertrain warranty applied (5 years, 60,000 miles)
• Explored the possibility of a separate TPS part (Part# 22620-4M511)
• Plan to experiment with repairing the TPS resistor board for future cases
• Saved the fleet $650 by utilizing the warranty coverage
• Additional option of remanufactured throttle assembly (Part# 1611K-AU00BRE) for a similar issue on another vehicle in the fleet

Case #4: Nissan

Vehicle Information

• 2005 Nissan Sentra, 1.8L

Issue + Repair History

• Goes to limp mode after driving for a while
• Codes P2135 (Throttle Body) and P0123
• Previous repairs: PCM, throttle body, and pedal assembly replaced

Other OBD2 Codes + Test Results

• Specific additional test results not provided

Suggestions from Community

• Location of connector F26 identified (passenger side kick panel)
• Recommendation to check idle and perform an Idle Air Volume Relearn
• F26 identified as a TCM harness connector

Final Fix

• Replaced PCM harness connector due to damage from previous testing
• The connector was sourced from a junkyard vehicle for easier replacement
• Issue resolved after replacement of the damaged connector

Case #5: Chevrolet

Vehicle Information

• 2008 Chevrolet Colorado LT, 2.9L

Issue + Repair History

• Intermittent poor idle quality, surge, and engine cutting out
• Previous repairs: Throttle body replaced, computer reprogrammed according to TSB, rewired new connector to throttle body

Other OBD2 Codes + Test Results

• P2135 (throttle position 1 2 correlation)
• Wiggle tests performed with no issues found

Suggestions from Community

• Check the wiring and connections thoroughly
• Examine the throttle body and related components again
• Consider the possibility of an intermittent electrical issue

Final Fix

• Found that someone had previously crimped the connector to the throttle body
• Removed all crimps and soldered them for a better connection
• After this repair, the customer reported no further problems

Advice	Description of Diagnostic Step
Check Warranty Coverage	Verify if the vehicle is still under warranty for the throttle body or related components.
Replace Throttle Body	If not covered by warranty, consider replacing the throttle body, especially if the TPS is integrated and non-serviceable.
Reflash/Update ECM	Update the Engine Control Module’s software to ensure it has the latest calibration and fixes.
Inspect and Clean Connections	Examine the electrical connections for the throttle body and sensors. Look for corrosion or loose connections and ensure they are secure.