Throttle Position Sensor 1 Circuit
1995-2005 Pontiac Sunfire 2.2L I4
Description
The PCM detected a malfunction in the Throttle Position Sensor 1 circuit. This code is set when the TP sensor signal is erratic or out of expected range during operation.
Symptoms
- Check Engine Light
- Erratic or no throttle response
- Reduced Engine Power mode
- Stalling
- Rough idle
Common Causes
- Faulty throttle position sensor
- Corroded TP sensor connector
- Damaged wiring to TP sensor
- Throttle body failure
- PCM failure (rare)
Diagnostic Steps
- Test TP sensor voltage at idle and WOT
- Inspect TP sensor connector for corrosion
- Check wiring continuity
- Monitor TP sensor with scan tool through range
- Test 5-volt reference supply
Repair Notes
Replace throttle position sensor or throttle body assembly. Clean connectors.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1120 on Other Vehicles
Pontiac Aztek
2001-2005 3.4L V6
Pontiac Bonneville
1990-1999 3.8L V6
Pontiac Bonneville
2000-2005 3.8L V6
Pontiac Bonneville GXP
2000-2005 4.6L V8
Pontiac Bonneville GXP
2000-2005 4.6L V8 Northstar
Pontiac Bonneville SSEi
1992-1999 3.8L Supercharged V6
Pontiac Bonneville SSEi
1992-1999 3.8L V6 Supercharged
Pontiac Firebird
1993-1997 3.4L V6
Common Questions
What does code P1120 mean on a 1995-2005 Pontiac Sunfire?
P1120 stands for "Throttle Position Sensor 1 Circuit". The PCM detected a malfunction in the Throttle Position Sensor 1 circuit. This code is set when the TP sensor signal is erratic or out of expected range during operation.
What are the symptoms of P1120 on a Pontiac Sunfire?
Common symptoms of P1120 include: Check Engine Light, Erratic or no throttle response, Reduced Engine Power mode, Stalling, Rough idle.
What causes P1120 on a 1995-2005 Pontiac Sunfire?
Common causes of P1120 include: Faulty throttle position sensor, Corroded TP sensor connector, Damaged wiring to TP sensor, Throttle body failure, PCM failure (rare).