Throttle/Pedal Position Sensor Maximum Stop Performance
Code P2166 indicates that the Engine Control Module (ECM) has detected a malfunction in the throttle/pedal position sensor circuit related to the maximum stop position. This typically means the sensor signal is out of expected range when the pedal is fully released or fully depressed, often due to a faulty sensor, wiring issues, or a misadjusted throttle stop.
1. Most Common Causes
- Faulty or worn accelerator pedal position (APP) sensor or throttle position sensor (TPS) 'D'
- Short circuit to voltage (Vref or signal) in the sensor 'D' circuit wiring
- Corroded, damaged, or loose pins in the sensor connector
- Misaligned or improperly installed sensor in its mounting
- Internal ECM/PCM failure (A/D converter or signal processing issue)
- Electromagnetic interference in the sensor wiring
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor throttle response or hesitation
- Unstable idle or stalling
- Inability to accelerate smoothly
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm code P2166 and check for related codes.
Step 2: Visually inspect the throttle/pedal position sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: Test the sensor voltage and resistance with a multimeter according to manufacturer specifications.
Step 4: Check throttle and pedal stop adjustments; ensure they are within spec.
Step 5: If sensor and wiring are okay, consider ECM reprogramming or replacement.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause reduced engine power, stalling, or unresponsive throttle, leading to unsafe driving conditions.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the sensor needs replacement or just cleaning/adjustment.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.