OBD-II Code P0222 — What It Means & How to Fix It

What Does This Error Mean?

P0222 means the ECM detected a lower-than-expected voltage signal from throttle position sensor B (TPS B). Modern electronic throttle systems use two sensors to monitor throttle position — P0222 is specifically about the second sensor (sensor B). A low voltage reading usually means a wiring problem, a bad sensor, or a damaged connector. Symptoms include hesitation when accelerating, the throttle not responding normally, limp mode activation, or the engine stalling.

Affected Models

All vehicles with electronic throttle control (drive-by-wire)
Common in Ford, GM, Chrysler, Toyota, Honda, and Nissan
Especially common in vehicles 2002 and newer
High mileage vehicles with worn throttle body sensors
Vehicles that have had throttle body cleaning recently

Common Causes

Worn or failed throttle position sensor B inside the throttle body
Broken or corroded wiring in the TPS signal circuit
Damaged or corroded TPS connector with bent or pushed-back pins
Short circuit to ground in the TPS B signal wire
Throttle body contaminated with carbon buildup interfering with sensor movement

How to Fix It

Check for companion codes. P0222 often appears alongside P0221 (TPS performance), P0223 (TPS B high voltage), or P2135 (TPS A/B voltage correlation). Fix the most fundamental code first.

If P2135 is also stored, the two sensors are disagreeing — this points strongly to a sensor or throttle body issue rather than simple wiring.
Inspect the throttle body wiring connector. Unplug it carefully and look for bent pins, green corrosion, or moisture inside. Clean with electrical contact cleaner.

A loose or corroded TPS connector is one of the most common fixes for low voltage sensor codes.
With a multimeter, test the voltage on the TPS B signal wire with the connector plugged in and the key on, engine off. The voltage should be within the range specified in your repair manual (usually 0.5 to 4.5 volts).

Consult your repair manual — the exact voltage range varies by manufacturer.
Clean the throttle body if it has significant carbon buildup. Use throttle body cleaner spray and a lint-free cloth. Carbon on the throttle blade can affect sensor readings.

Some vehicles — particularly many newer BMWs and other European cars — should NOT have solvent sprayed into the throttle body. Check your manual first.
If voltage remains low after cleaning and inspecting the connector, the throttle position sensor or entire throttle body likely needs replacement. On most modern vehicles, the sensor and throttle body are one unit.

After replacement, some vehicles require a throttle body relearn procedure with a scan tool before the idle will stabilize.

When to Call a Professional

Many newer vehicles integrate the throttle position sensor directly into the throttle body — they cannot be replaced separately. Replacing the entire throttle body can cost $150 to $500 depending on the vehicle. A professional can confirm with a live data scan whether the sensor voltage truly is low or if the wiring is the fault. Do not attempt to clean the throttle body without looking up whether it is safe for your specific throttle body design.

Frequently Asked Questions

What is the difference between P0222 and P0121?

P0121 relates to throttle position sensor A (the primary sensor), while P0222 relates to sensor B (the secondary sensor). Electronic throttle bodies use two sensors as a safety check — if they disagree significantly, the ECM triggers a fault. Both codes indicate a low voltage condition on their respective sensors.

Will P0222 put my car in limp mode?

Yes, it often does. Electronic throttle faults typically trigger limp mode to prevent unsafe throttle behavior. In limp mode, throttle response is limited and engine power is reduced. The car is still drivable for getting to a shop, but it will feel sluggish and may not rev above 3,000 RPM.

Can I fix P0222 myself?

Yes, if the cause is a dirty throttle body or corroded connector. Both of those are DIY-friendly repairs. If the throttle body sensor needs replacement, and it is integrated into the throttle body, you will need to buy and install a new throttle body — which is a moderate DIY job on most vehicles.