P0225

Code

Generic P — Powertrain

Throttle/Pedal Position Sensor/Switch C Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 32 EN: 67 RU: 34

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Page language: EN

Causes

Open or shorted wiring in the TPS/pedal sensor C circuit
Poor or corroded connector(s) at sensor or PCM
Intermittent or low reference voltage (5 V) or poor ground
Failed throttle/pedal position sensor (internal fault)
Water intrusion or physical damage to sensor or harness
PCM internal fault (rare) or software/calibration issue

Symptoms

MIL/Check Engine light illuminated
Reduced engine power / limp-home mode
Poor or inconsistent throttle response, hesitation
Engine may idle poorly or stall
Inability to accelerate normally

What to check

Read freeze frame and full DTC description with a scan tool; note related codes
Visual inspection of pedal/throttle sensor connector and wiring for corrosion, damage, pin pushed out
Check for Technical Service Bulletins (TSBs) related to TPS or harness
Verify reference 5 V and ground at the sensor with ignition ON using a DVOM
Backprobe sensor signal and compare voltage to expected range while moving pedal
Wiggle test wiring while monitoring live data for intermittent changes

Signal parameters

Reference voltage: typically ~5.0 V (key ON, engine OFF)
Signal voltage: varies with pedal position; expected ~0.5–4.5 V across range (model dependent)
Low-voltage fault: signal near 0.0–0.2 V indicates short to ground/open circuit
High-voltage fault: signal near 4.8–5.0+ V indicates short to 5 V or open reference
Sensor C often used for redundant/correlation checks vs other TPS channels

Diagnostic algorithm

Connect an OBD-II scan tool, record freeze frame, clear codes and attempt to reproduce. Note if code returns immediately or intermittently.
Perform a careful visual inspection of the pedal/throttle sensor and harness (look for chafing, pin corrosion, water intrusion).
Backprobe the sensor connector with ignition ON (engine OFF). Verify the 5 V reference and ground presence/quality with a DVOM.
Measure the sensor signal voltage while slowly moving the accelerator pedal. Signal should change smoothly without dropouts or sudden jumps.
If voltage is stuck low/high or erratic, trace wiring continuity from sensor to PCM. Repair any opens/shorts, especially near harness entry points and connectors.
Wiggle the harness and connector while monitoring live data to detect intermittent faults. Check connector pins for corrosion or looseness.
If wiring and supply are good but signal is incorrect, replace the pedal/throttle position sensor per factory procedure. Do not substitute parts without verifying compatibility.
After repair or replacement, clear codes and perform a test drive / re-test with scan tool to confirm the code does not return and that throttle control is normal.
If fault persists with good wiring and a new sensor, consider PCM input circuit testing or replacement and consult vehicle-specific service information.

Likely causes

Damaged or corroded connector/wiring at the pedal/throttle sensor
Sensor C internal failure
Broken/disconnected ground or 5 V reference wire
Short to battery or chassis ground caused by worn harness

Fault status

⚠️ Status

PCM detected abnormal voltage or circuit fault on Throttle/Pedal Position Sensor C. Possible open, short, poor reference/ground, or sensor failure. Service required to inspect wiring and sensor.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours