P0222
Throttle/Pedal Position Sensor/Switch B Circuit Low Input
If your vehicle's onboard computer has flagged the diagnostic trouble code P0222, it refers to a detected anomaly regarding "Throttle/Pedal Position Sensor/Switch B Circuit Low Input". This systemic engine fault needs a targeted check before symptoms expand.
Driver's Summary
Code P0222 means your vehicle detected a problem with the throttle/pedal position sensor/switch b circuit low input system. The most common signs are check engine light, vehicle stuck at idle or limp mode. Given the high severity of this code, continuing to drive risks significant mechanical damage. Have it diagnosed immediately.
Symptoms
Check engine light, vehicle stuck at idle or limp mode
Common Causes
- Short to ground in TPS circuit
- Defective TPS sensor
- Failed 5V reference from PCM
- Water intrusion in connector
How to Fix
- 1 Repair shorted wire
- 2 Replace TPS sensor
- 3 Test PCM 5V output
- 4 Dry and dielectric grease connector
Technical Explanation
P0222 is stored after the control module confirms the fault over multiple ignition cycles, ruling out transient electrical noise as the cause. For injector-specific codes, the ECM monitors the injector control circuit voltage drop during each pulse; a shorted or open injector presents a characteristic resistance signature that differs measurably from a healthy unit. Once confirmed, the code is stored as a permanent DTC and the MIL is activated. The freeze frame snapshot — recording RPM, load, coolant temperature, and fuel trim at fault detection — is also saved and is critical for accurate diagnosis.
Is It Safe to Drive?
With P0222 active, your engine or transmission is not operating within design parameters. Short-term driving may seem fine, but internal damage is accumulating — particularly to short to ground in tps circuit.
Mechanic's Pro Tip
The most common mistake with P0222 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
Wiring repair: $100; TPS replacement: $100 - $300