P1574

Code

LAND ROVER P — Powertrain

Throttle position sensor disagreement between sensors

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 10 EN: 18 RU: 19

AI status

Completed

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Completed 100%

Page language: EN

Faulty throttle position sensor (TPS) or accelerator pedal position sensor
Wiring harness damage: open, short to ground or to battery, or corrosion in connectors
Poor connector pin contact or water intrusion
Incorrect sensor mounting or mechanical misalignment
Dirty or sticking throttle plate or linkage interfering with sensor reading
Intermittent reference voltage or ground (battery/charging system issues)

Scan for codes, record freeze-frame data and related/secondary codes
Monitor live data for both TPS/APP sensor outputs across key positions (closed, partial, WOT)
Compare sensor voltage/percent readings for correlation and response to pedal/throttle movement
Check battery voltage and charging system while testing
Visually inspect connectors and wiring for damage, corrosion or pin push-out
Backprobe reference (usually 5 V) and ground at sensor with key on, engine off

Reference voltage: typically ~5.0 V (check vehicle spec)
TPS/APP idle voltage: commonly ~0.4–1.0 V (or 0–10% on percentage readout)
TPS/APP WOT voltage: commonly ~4.0–4.8 V (or ~90–100% on percentage readout)
Expected correlation: both sensors should rise smoothly and track each other within manufacturer tolerance (often a few percent or a fixed voltage delta)
Open circuit: approx. infinite resistance on signal wire
Short to ground: signal ~0 V; short to battery: signal ~battery voltage

Read and record all stored DTCs, freeze frame and pending codes. Note battery voltage during freeze frame.
Clear codes and perform a road or key-on/static test while monitoring live TPS/APP values to reproduce the issue.
With key ON engine OFF, backprobe sensor pins: verify reference voltage (~5 V), sensor signal voltage at rest, and good ground. Compare both sensors.
Move throttle/pedal through full travel while watching both sensor values; look for noisy, stuck, non-linear or non-correlating signals.
Inspect connectors and wiring for corrosion, broken strands, chafing, or pin damage; repair any issues found and re-test.
If wiring and connectors are good, perform continuity and short-to-power/ground tests between sensor signal, reference, and PCM pins.
Use a lab scope to compare actual waveforms/signals from both sensors during operation to detect noise, dropouts or voltage spikes.
If one sensor is out of spec, replace the faulty TPS or throttle body (if integrated). If sensors are external, replace only the defective sensor.
After repair or replacement, perform specified throttle/APP relearn/calibration procedure and clear codes. Re-check for proper correlation and road test.
If symptoms persist despite correct sensors and wiring, consider PCM diagnosis/reflash or replacement as last resort.

⚠️ Status

Throttle position sensor disagreement — TPS/APP sensor outputs do not correlate within expected tolerance.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours