P1120
FordThrottle position sensor out of range
Medium SeverityThe throttle position sensor (TPS) signal is out of expected range. This messes with the engine's fuel and air mix, leading to rough running or limited throttle.
⚠️ Before You Begin (Safety First)
Engine might stall unexpectedly. Always work on a cool engine. Disconnect the battery before electrical work.
Common Symptoms
- Rough idle
- Hesitation during acceleration
- Engine may stall
- Reduced engine power
- Check Engine Light illuminated
Common Causes
- Faulty throttle position sensor (TPS)
- Damaged or corroded wiring to the TPS
- Poor electrical connection at the TPS harness
- Faulty Powertrain Control Module (PCM) (less common)
Frequently reported on: Ford F-150 (1997-2004), Ford Ranger (1998-2006), Ford Expedition (1997-2006), Ford Focus (2000-2004)
Diagnostic Steps
- Inspect the throttle position sensor (TPS) connector for corrosion or damage. Make sure it's snug.
- Check the wiring harness leading to the TPS for any frayed, cut, or exposed wires.
- Use a multimeter to test the TPS signal voltage if you know how. Look for smooth voltage changes when the throttle is moved.
- If tests indicate a bad TPS, remove the old sensor (usually a couple of screws) and install a new one.
- Clear the P1120 code using an OBD-II scanner and test drive the vehicle to confirm the fix.
👨🔧 When to Call a Professional
If the new TPS doesn't fix it, or you're getting other codes too, it's time to get it to the shop. Don't chase ghosts.
Commonly Asked Questions
What's a P1120 mean for my Ford?
It means the throttle position sensor is sending a signal that the computer doesn't like. It's out of whack.
Can I keep driving with this code?
Nah, I wouldn't. The engine can stumble or even quit on you. Not safe on the road.
Is changing the TPS a hard job?
It's usually a pretty straightforward swap. Two screws, a plug. Anyone with a wrench can do it.
What if I replace the TPS and the code comes back?
Then you've got to dig deeper. Check the wires for damage. Could even be the computer, but that's less common.