Throttle Position Sensor Circuit Intermittent
The P0124 code indicates that the Engine Control Module (ECM) has detected an intermittent signal from the throttle position sensor (TPS) circuit. This sensor monitors the throttle plate angle and sends a voltage signal to the ECM. An intermittent fault means the signal is erratic or drops out temporarily, often due to wiring issues, poor connections, or a failing sensor. This can cause unpredictable engine behavior.
1. Most Common Causes
- Loose, corroded, or damaged connections at the TPS/APP sensor connector
- Wiring with intermittent opens or shorts due to chafing, bending, or heat damage in the harness
- Internally deteriorated throttle position sensor (TPS) causing intermittent failure
- Accelerator pedal position (APP) sensor with erratic signal
- Voltage reference or ground circuit issues for the sensor
- Intermittent ECM/PCM failure (less common)
2. Symptoms You Will Notice
- Check Engine Light on
- Engine hesitation or surging during acceleration
- Intermittent stalling or rough idle
- Reduced power or limp mode activation
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to capture conditions when fault occurred.
Step 2: Visually inspect TPS wiring and connector for damage, corrosion, or loose pins.
Step 3: Use a multimeter to check TPS reference voltage (5V) and signal voltage (varies with throttle position).
Step 4: Monitor TPS signal with a scan tool while wiggling wiring harness to reproduce intermittent fault.
Step 5: If signal is erratic, replace TPS and repair any wiring issues.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended as intermittent TPS signal can cause sudden loss of power or stalling, posing a safety risk.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on sensor cost and accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.