P1120

Code

Other P — Powertrain

Throttle position sensor out of range

Brand: Other

Type: P — Powertrain

Views: UK: 45 EN: 238 RU: 52

AI status

Completed

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Page language: EN

Causes

Faulty throttle position sensor (potentiometer or Hall-effect sensor)
Damaged wiring harness or connector (short to power/ground, open, high resistance)
Intermittent or lost 5 V reference or ground to the TPS
Corroded or loose connector pins
Mechanical sticking or misaligned throttle plate / throttle body
Aftermarket throttle or improper installation

Symptoms

Check Engine Light (MIL) illuminated
Poor or erratic idle
Sudden loss of throttle response or reduced engine power (limp mode)
Surging or hesitation on acceleration
Stalling at idle or during low-speed maneuvers
Throttle pedal input not matching engine response

What to check

Read freeze frame and freeze-data with a scan tool; record TPS PID and throttle angle at key on and during cranking
Visual inspection of TPS connector and wiring for damage, corrosion, pin push-out, or rodent chew
Back-probe TPS connector to verify 5 V reference (or manufacturer reference), signal voltage, and ground continuity with engine off and key on
Check signal voltage changes smoothly when moving throttle by hand (no jumps or dropouts)
Measure resistance (if applicable) across TPS sensor pins per service manual
Inspect throttle body for carbon buildup, sticking throttle plate, or mechanical interference

Signal parameters

Typical closed-throttle TPS voltage: ~0.1–1.0 V (varies by manufacturer)
Typical wide-open throttle TPS voltage: ~4.0–4.9 V (varies by manufacturer)
Signal should change smoothly and monotonically with throttle movement (no dead spots or sudden jumps)
5 V reference (or specified supply) present at TPS reference pin with key on
Low resistance to ground on TPS ground circuit; no high resistance or intermittent

Diagnostic algorithm

Retrieve codes and live data: record TPS voltage/PID at closed throttle and at wide open; note freeze frame.
Visual inspection: check TPS connector, wiring harness routing, shielding, and ground points for damage or corrosion.
Test reference and ground: with key on (engine off) back-probe connector to confirm stable 5 V reference and good ground.
Verify signal behavior: slowly move throttle by hand (or operate throttle) while watching TPS voltage — it must ramp smoothly from low to high without spikes or dropouts.
Check continuity/resistance: with ignition off, measure continuity from TPS ground to chassis ground and from PCM reference to TPS reference; repair any open/high-resistance circuits.
Wiggle test: with connector connected and engine running or key on, gently wiggle harness near TPS to reproduce fault; monitor for intermittent changes.
Swap/compare: if available, compare TPS output to another identical sensor or use scan tool to compare accelerator pedal position vs. TPS (correlation checks).
Clean/inspect throttle body: remove carbon that may stick throttle plate; check for smooth mechanical travel.
Repair harness or connector faults: repair broken wires, replace corroded terminals, or replace harness as needed.
Replace TPS only after verifying wiring and reference/ground are good. After replacement, perform required relearn/calibration procedure per manufacturer.
Clear codes and road test under various conditions to confirm repair; verify no recurrence.

Likely causes

Wiring open or short on TPS signal, reference, or ground
Failed TPS sensor element (wear on potentiometer or failed Hall sensor)
Corroded/poor connector contact at TPS
Throttle body mechanical fault or contamination affecting throttle plate travel
Missing PCM calibration / failed relearn after replacement

Fault status

⚠️ Status

TPS signal out of range: PCM detected TPS voltage/position outside allowable limits. Possible sensor, wiring, or throttle body issue. Vehicle may have reduced throttle response.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours