P1252

Code

Other P — Powertrain

Pedal Correlation PDS1 and LPDS High

Brand: Other

Type: P — Powertrain

Views: UK: 41 EN: 57 RU: 37

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Page language: EN

Causes

Faulty pedal position sensor (PDS1 or LPDS)
Short to battery (12V) on sensor signal or reference circuit
Open or high-resistance ground to pedal sensor(s)
Damaged connector pins, corrosion or poor contact
Broken/damaged wiring or chafed harness between sensor and ECU
Mechanical binding or mis-adjusted pedal assembly

Symptoms

Check Engine Light (MIL) illuminated
Reduced engine power or limp-home mode
Delayed or inconsistent throttle response to pedal movement
Vehicle hesitates, surges, or idles poorly
Stored multiple pedal or throttle related DTCs

What to check

Read and record freeze frame and all related DTCs with a scan tool
Verify battery voltage and note any low-voltage events
Inspect pedal assembly, sensor connectors and wiring for damage, corrosion or water
Backprobe pedal sensor connector and measure reference voltage (key ON, engine OFF)
Monitor live data for PDS1 and LPDS while pressing pedal slowly from rest to full travel
Perform wiggle test on wiring and connectors while observing live sensor values and for flicker/changes

Signal parameters

Reference voltage: typically ~5.0 V (key ON, engine OFF) — verify OEM spec
Sensor ground: ~0 V (solid low resistance to chassis/ECU ground)
Output ranges: commonly about 0.5 V (idle/not pressed) to ~4.5 V (full pedal) — consult vehicle spec
Correlation: both pedal sensors should change smoothly and proportionally; delta between sensors should remain small and follow OEM threshold (often
No sudden jumps, dropouts, or fixed high voltage near battery voltage (≈12 V) on signal lines

Diagnostic algorithm

Safety first: park, chock wheels, key OFF. Use OEM repair manual and follow safety procedures.
Connect an advanced scan tool and retrieve all codes and freeze frame data. Note related throttle/pedal codes.
With key ON (engine OFF) measure reference voltage at pedal sensor connector. Compare to spec (~5 V). If missing or low, inspect ECU fuse, supply, and wiring.
Measure sensor outputs (PDS1 and LPDS) at connector while slowly pressing pedal. Verify outputs change smoothly from low to high and are within specification.
If either sensor output is fixed high or reads near 12 V, remove harness power or check for short to battery on that signal. Disconnect sensor and re-measure for open/short.
Check sensor ground continuity to chassis and ECU ground. Repair any high-resistance connection.
Inspect connectors and wiring for corrosion, bent pins, water intrusion, or physical damage. Repair or replace as needed.
Perform wiggle test on wiring while monitoring live data. If fault is intermittent, use backprobe and oscilloscope if available to detect noise or spikes.
If wiring and connectors are good but a sensor reads incorrectly, replace the faulty pedal position sensor (follow OEM replacement and calibration procedure if required).
After repairs, clear codes, perform relearn/calibration procedures required by manufacturer, and road test while monitoring pedal sensors for proper correlation.
If problem persists after sensors and wiring verified/replaced, consider ECU fault and consult manufacturer procedures for ECU testing or replacement.