🚨 Diagnostic Profile
Vehicle Make: ACURA
Technical Description: Closed Throttle Position Insufficient
This diagnostic trouble code indicates that the Engine Control Module (ECM) has detected that the throttle position sensor (TPS) signal voltage is lower than the expected value when the throttle is supposed to be in the fully closed (idle) position. This typically points to an issue within the electronic throttle body assembly, wiring harness, or the ECM’s interpretation of the closed throttle voltage range.
🚨 Repair Difficulty Tier
Difficulty Rating: Intermediate
This repair requires the use of a professional-grade OBD-II scan tool capable of reading live sensor data (PIDs) and performing throttle body relearn procedures. A digital multimeter is also necessary to test wiring continuity and sensor voltage output. While no specialized module flashing is typically required, the calibration and relearn process demands precision and familiarity with electronic throttle control systems. This is not recommended for beginners due to the risk of improper idle calibration affecting drivability.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Begin by visually inspecting the throttle body assembly for carbon buildup, debris, or physical damage around the throttle plate that could prevent it from fully closing. Check the electrical connector at the throttle body for corrosion, bent pins, or loose connections. Trace the wiring harness from the throttle body back to the ECM, looking for chafing, pinches, or rodent damage. Inspect the throttle body mounting for any signs of vacuum leaks or gasket failure that could affect airflow readings at idle.
Step 2: Diagnostic Verification
Connect an OBD-II scan tool and access live data parameters, specifically monitoring the Throttle Position Sensor (TPS) voltage and Accelerator Pedal Position (APP) sensor readings. With the key on and engine off, the TPS voltage at closed throttle should typically read within the manufacturer’s specified range (commonly 0.5V to 1.0V depending on the model year). Use a digital multimeter to backprobe the TPS connector and verify voltage output matches scan tool data. Check for any correlating codes related to the APP sensor or ECM communication faults. If voltage readings are erratic or out of range, this confirms a sensor or wiring fault rather than a mechanical throttle plate issue.
Step 3: Resolution & Reset Process
If the throttle body assembly is confirmed faulty, replace the electronic throttle body unit as a complete assembly, as the TPS is typically non-serviceable separately on most Acura models. After installation, clear all stored diagnostic trouble codes using the scan tool. Perform the manufacturer-specified throttle body relearn or idle learn procedure, which often requires the engine to be at operating temperature with all accessories off. Verify successful calibration by rechecking live TPS data at idle and during a test drive to confirm the Check Engine Light does not return and idle quality is smooth.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: Electronic Throttle Body Assembly (OEM recommended), OBD-II diagnostic scan tool with live data and relearn capability, digital multimeter, dielectric grease for connector reassembly.
Average Component Price: $180 – $450 for an OEM throttle body assembly, depending on the specific Acura model and year. Aftermarket units may range from $120 – $250 but are not always recommended for precision-sensitive throttle control systems.
Estimated Labor Hours: 1.0 to 1.8 hours for diagnostic testing, throttle body replacement, and relearn procedure, depending on engine bay accessibility and model-specific mounting configuration.