Throttle Position Sensor Out of Range Low
2000-2000 Mazda MX-5 Miata 1.8L I4
The 2000 Mazda MX-5 Miata is equipped with a 1.8L inline-4 engine. Below you'll find detailed p1120 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
The Throttle Position sensor signal is below the minimum expected voltage. The PCM sees a voltage lower than the normal idle-position threshold, which can trigger limp mode on electronic throttle systems.
Symptoms
- Check Engine Light
- Poor acceleration
- Idle surge
- Engine stalling
- Limp mode
Common Causes
- Faulty TP sensor
- Wiring short to ground
- Loose TP sensor connector
- TP sensor misadjusted on cable-actuated throttle
- Corroded connector pins
Diagnostic Steps
- Check TP sensor voltage at idle (should be approximately 0.5-1.0V)
- Inspect wiring for shorts to ground
- Check connector for corrosion or looseness
- Test TP sensor through full range with multimeter
- Verify 5V reference voltage
Repair Notes
Replace the TP sensor if faulty; repair wiring if shorted to ground.
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
Common Questions
What does code P1120 mean on a 2000-2000 Mazda MX-5 Miata?
P1120 stands for "Throttle Position Sensor Out of Range Low". The Throttle Position sensor signal is below the minimum expected voltage. The PCM sees a voltage lower than the normal idle-position threshold, which can trigger limp mode on electronic throttle systems.
What are the symptoms of P1120 on a Mazda MX-5 Miata?
Common symptoms of P1120 include: Check Engine Light, Poor acceleration, Idle surge, Engine stalling, Limp mode.
What causes P1120 on a 2000-2000 Mazda MX-5 Miata?
Common causes of P1120 include: Faulty TP sensor, Wiring short to ground, Loose TP sensor connector, TP sensor misadjusted on cable-actuated throttle, Corroded connector pins.
Last updated: March 2026