Code
P1275
CHRYSLER
P — Powertrain
Accelerator Pedal Position (APP) Sensor 1 Circuit
Views:
UK: 20
EN: 46
RU: 27
AI status
Completed
Completed
100%
Causes
- Damaged or corroded APP sensor connector or wiring
- Open or shorted signal wire to PCM (short to battery or ground)
- Faulty APP sensor (internal failure)
- Poor or missing reference 5V or ground to the APP sensor
- Faulty PCM or poor PCM connector/circuit
- Intermittent connector contact (moisture, corrosion, pin damage)
Symptoms
- Reduced engine power / limp mode
- Check Engine Lamp (MIL) illuminated
- Unresponsive, hesitant, or inconsistent throttle response
- Engine may idle poorly or surge
- Stored related throttle or pedal correlation codes
- Cruise control may be disabled
What to check
- Read DTCs and freeze frame with a capable scan tool; record live APP sensor values
- Visual inspection of pedal area connectors, wiring, and PCM connector for damage or corrosion
- Backprobe APP sensor connector and measure reference voltage (usually +5 V) and ground presence
- Measure APP Sensor 1 signal voltage at rest and while pressing pedal — expect monotonic rise (approx. 0.5–4.5 V)
- Compare APP Sensor 1 to APP Sensor 2 (if present) for correlation and similar voltage sweep
- Check for continuity and shorts between signal, reference, and ground circuits to chassis and battery
Signal parameters
- Reference voltage to APP sensor: ~5.0 V (regulated by PCM)
- Sensor 1 idle signal: typically ~0.5–1.0 V (may vary by model)
- Sensor 1 full travel signal: typically ~4.0–4.5 V
- Sensor output should change smoothly and monotonically with pedal travel (no drops, spikes, or flat spots)
- Signal wire should not be shorted to battery voltage or to ground
Diagnostic algorithm
- Confirm P1275 with scan tool, clear codes, and see if it returns. Note freeze frame and related codes (e.g., throttle actuator or APP sensor codes).
- Perform a visual inspection of the APP sensor harness, connector, and PCM connector. Repair obvious damage, corrosion, or loose pins.
- With key ON (engine off), backprobe the APP connector: verify ~5 V reference and a good ground circuit. If reference or ground missing, trace to PCM and repair.
- Measure sensor 1 signal voltage at rest and while slowly depressing the pedal — expect a smooth change from ~0.5 V to ~4.0–4.5 V. If the signal is stuck, erratic, or out of range, suspect the sensor or wiring.
- Compare Sensor 1 signal to Sensor 2 (if present) using live data. If sensors disagree or are not correlated, this supports sensor or wiring fault.
- Check continuity of signal, reference and ground wires between APP connector and PCM connector; inspect for shorts to battery or ground. Repair any open/shorted wiring.
- If wiring and connectors are good but the waveform or voltages are incorrect, replace the APP sensor, retest, and recheck live data.
- If replacement sensor does not clear the issue, inspect PCM connector and pins. If wiring to PCM checks good and new sensor still fails, consider PCM fault and consult manufacturer procedures before replacement.
- After repairs, clear codes, verify live data operation, and perform a road test to confirm the fault does not return.
Likely causes
- Wiring harness chafing at common pinch points near pedal or firewall
- Corroded or bent pins at pedal sensor connector
- Sensor failed due to age, impact or contamination
- Loose PCM connector or damaged circuit inside PCM
- Improperly routed or pinched replacement harness after prior work
Fault status
Status
DTC P1275 — Accelerator Pedal Position (APP) Sensor 1 Circuit: PCM detected an abnormal condition (open, short, out-of-range, or poor correlation) on the APP Sensor 1 circuit. This may cause throttle limp-in and reduced engine performance until repaired.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email