What Does P0227 Mean?
This code indicates the throttle/pedal position sensor/switch C circuit is reading lower than the ECM's minimum expected voltage, typically below 0.2V. This low input suggests the sensor has failed internally, the signal wire is shorted to ground, or the reference voltage has been lost.
Common Causes
35%
Failed pedal or throttle position sensor C with internal short to ground producing near-zero output voltage
30%
Signal wire shorted to ground from chafing, water damage, or insulation breakdown in the footwell area
20%
Lost 5V reference to sensor C from an open reference wire or overloaded shared reference circuit
15%
Water intrusion in the pedal sensor connector creating a low-resistance path between signal and ground
Diagnostic Steps
1
Step 1: Measure sensor C signal voltage at the pedal connector with key on. A reading below 0.2V confirms the low input. Normal rest position voltage should be 0.5-1.0V.
2
Step 2: Disconnect the pedal sensor connector and check signal voltage at the ECM harness side. If it rises, the sensor is shorted internally.
3
Step 3: Verify 5V reference voltage at the pedal connector. If missing, trace the reference supply wire for opens.
4
Step 4: Check for shorts to ground on the sensor C signal wire by measuring resistance from the signal pin to chassis ground with everything disconnected. Should be OL.
5
Step 5: Inspect the pedal area for water damage, especially on vehicles with known water leaks around the windshield or A-pillar that direct water into the footwell.
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
This code indicates the throttle/pedal position sensor/switch C circuit is reading lower than the ECM's minimum expected voltage, typically below 0.2V. This low input suggests the sensor has failed internally, the signal wire is shorted to ground, or the reference voltage has been lost.
The most common cause of P0227 (Throttle/Petal Position Sensor/Switch C Circuit Range/Performance Problem) is: Failed pedal or throttle position sensor C with internal short to ground producing near-zero output voltage
Typical repair costs for P0227 range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A low sensor C reading forces the ECM into failsafe mode with severely limited throttle response. The vehicle can typically still be driven at reduced speed to a repair facility.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0227 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control System
Difficulty
Type
Generic (SAE)
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