Throttle Position Sensor 1 Circuit
2000-2005 Chevrolet Impala 3.8L V6
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
Chevrolet Astro
1995-2005 4.3L V6 Vortec
Chevrolet Avalanche
2002-2006 5.3L V8 Vortec
Chevrolet Avalanche
2002-2006 8.1L V8 Vortec
Chevrolet Avalanche
2007-2013 5.3L V8 Vortec
Chevrolet Avalanche
2007-2013 6.0L V8 Vortec
Chevrolet Aveo
2012-2018 1.6L I4
Chevrolet Beat
2018-2021 1.2L I4
Chevrolet Beretta
1990-1996 2.2L I4
Common Questions
What does code P1120 mean on a 2000-2005 Chevrolet Impala?
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 Chevrolet Impala?
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 2000-2005 Chevrolet Impala?
Common causes of P1120 include: Faulty throttle position sensor, Corroded TP sensor connector, Damaged wiring to TP sensor, Throttle body failure, PCM failure (rare).