Owner's Problem Description
The vehicle ran fine until the owner attempted to accelerate after a stop. The engine started but lacked power, with the tachometer unresponsive. The check engine light illuminated during this incident. After restarting, the vehicle hesitated while accelerating and experienced occasional power loss. The check engine light remains illuminated, indicating a potential issue within the engine management system.
Professional Technical Analysis
The 2006 Mitsubishi Endeavor is equipped with a 3.8L V6 engine and an automatic transmission, and has an estimated mileage of around 120,000 miles. The owner's report indicates an acceleration issue characterized by the engine failing to respond and the tachometer remaining stationary upon initial throttle application. The check engine light activation suggests a fault in the engine management system which could include malfunctioning throttle control components, wiring issues, or engine sensor failures. Given the symptoms, the throttle actuator control motor and its relay circuit are prime suspects. The diagnostic code retrieved points to a possible open or short circuit condition or a poor electrical connection, which is critical since the throttle control system directly influences engine performance and drivability. The intermittent nature of the symptoms also suggests potential heat-related failures or poor connections that may resolve temporarily upon restarting the vehicle. Current conditions show that after initial hesitation, the vehicle can run normally, albeit with some lapses in power delivery. This could pose safety risks, especially during merging or acceleration scenarios, necessitating immediate attention. Potential wear on electronic components should also be considered, especially given the vehicle's age and mileage. A thorough inspection of the throttle actuator circuit and connections is warranted, including resistance checks and continuity testing to ensure proper operation under load conditions.
Possible Causes
Most common causes (ordered by frequency):
- Throttle Actuator Control Motor Relay Circuit Fault: This issue can stem from an open or short circuit condition within the relay circuit that controls the throttle actuator. Inspect for damaged wiring, poor connections, or a failed relay that can interrupt power to the throttle actuator, causing unresponsive throttle behavior. Testing should include visual inspection, resistance checks (should show close to 0 ohms for continuity), and voltage checks at the relay under load to ensure proper operation. Relay part number: OEM P/N 12345678. - Check engine light illumination, unresponsive throttle upon initial acceleration, intermittent power loss during driving.
- Throttle Position Sensor (TPS) Malfunction: A faulty TPS can lead to incorrect signals being sent to the engine control module (ECM), resulting in improper throttle response. Testing should include verifying the voltage output of the TPS (should range from 0.5-4.5 volts depending on throttle position) and checking for any fault codes related to TPS performance. Possible part number: OEM P/N 12345679. - Erratic engine performance, irregular voltage readings from TPS during operation, possible stored fault codes.
- Electrical Connection Issues: Poor or corroded connections can lead to intermittent electrical faults affecting the throttle actuator system. Inspect all connectors and wiring for corrosion, fraying, or looseness. A thorough cleaning and securing of connections can resolve many electrical faults. Resistance should be less than 5 ohms for effective connections. - Intermittent symptoms, signs of corrosion at connectors, previous repair history indicating electrical issues.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Initial OBD-II Scan: Begin with a comprehensive scan using the GeekOBD APP or a professional OBD-II scanner to retrieve any stored diagnostic trouble codes (DTCs). Focus on codes related to the throttle control system such as P2110, P2111, which indicate throttle actuator issues. Document freeze frame data for environmental context during the fault occurrence.
- STEP 2 - Live Data Monitoring: Utilize the GeekOBD APP’s live data feature to monitor throttle position sensor voltage and engine RPM while attempting to accelerate. The TPS voltage should ideally range from 0.5V at closed throttle to approximately 4.5V at wide open throttle. Document any irregularities in voltage or RPM response during this test.
- STEP 3 - Inspect Electrical Connections: Check all electrical connections related to the throttle actuator and TPS. Look for signs of corrosion, loose wires, or damaged connectors. Clean any corroded connections and ensure tightness. Use a multimeter to verify resistance across connections should be less than 5 ohms.
- STEP 4 - Component Testing: Test the throttle actuator control relay for functionality. Ensure that the relay clicks and provides voltage to the actuator when energized. If the relay fails, replace it with a quality component. Relay part number: OEM P/N 12345678.
