🚨 Diagnostic Profile
Vehicle/Equipment Make: ACURA
Technical Description: Throttle Position Lower Than Expected
This diagnostic trouble code indicates that the Engine Control Module (ECM) has detected that the throttle position sensor (TPS) or the electronic throttle body’s actual position signal is reading lower than the value the ECM is commanding or expecting based on accelerator pedal position, engine load, and other input parameters. This is common on Acura’s Drive-By-Wire (DBW) electronic throttle control systems and can stem from a mechanical binding issue, a wiring/connector fault, a failing throttle position sensor, or an out-of-calibration throttle body requiring a relearn procedure.
🚨 Repair Difficulty Tier
Rating: Intermediate
This repair typically requires a capable OBD-II scan tool with live data streaming and bi-directional control capability (to perform a Throttle Body Relearn/Reset procedure), along with a digital multimeter to check wiring integrity and sensor voltage output. While no airbag or restraint systems are involved, the throttle body relearn procedure and accurate voltage diagnostics require more than basic hand tools, placing this outside a true beginner-level repair.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
- Visually inspect the throttle body for carbon buildup, debris, or physical binding of the throttle plate that could restrict it from reaching its commanded position.
- Check the electrical connector at the throttle body for corrosion, bent pins, or a loose connection.
- Inspect the wiring harness between the ECM and throttle body assembly for chafing, pinches, or rodent damage, particularly near the intake manifold and firewall pass-through points.
- Confirm the throttle body mounting bolts are secure and there is no vacuum leak affecting airflow readings.
Step 2: Diagnostic Verification
- Connect an OBD-II scan tool capable of reading live Acura ECM data streams; compare ‘Commanded Throttle Position’ against ‘Actual Throttle Position’ side by side while slowly increasing throttle input.
- Use a digital multimeter to check the reference voltage (typically 5V) and ground circuits at the throttle position sensor connector with the key on, engine off.
- Backprobe the TP sensor signal wire and verify voltage rises smoothly and proportionally as the throttle is manually opened (with engine off and connector attached).
- Check for any additional stored codes related to the Accelerator Pedal Position (APP) sensor, which could indicate a mismatch between pedal input and throttle response.
Step 3: Resolution & Reset Process
- If the throttle body is dirty or gummed up, clean it thoroughly using approved throttle body cleaner (avoid spraying directly into electronic sensor components).
- If wiring or connector damage is found, repair or replace the affected harness section and connector.
- If the sensor itself is out of range or non-linear, replace the throttle body assembly (most Acura models integrate the TPS within the throttle body unit, non-serviceable separately).
- After any throttle body replacement or connector disturbance, perform the mandatory Throttle Body Relearn/Idle Reset procedure using the scan tool per Acura service specifications to allow the ECM to recalibrate the closed-throttle and full-throttle position values.
- Clear all stored codes and perform a test drive through varying throttle inputs and idle conditions to confirm the actual throttle position now tracks correctly with the commanded position.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: Electronic Throttle Body Assembly (if faulty), Throttle Body Connector/Pigtail Harness (if damaged), OBD-II Scan Tool with Acura-specific bi-directional relearn capability, Digital Multimeter, Throttle Body Cleaner.
Average Component Price: $150 – $450 for a new/remanufactured OEM throttle body assembly; $30 – $80 for wiring harness repair components; Diagnostic scan tool relearn typically included in shop diagnostic fee (no separate dealer software flash usually required for this code).
Estimated Labor Hours: 1.0 – 2.0 hours for diagnosis and testing; an additional 0.5 – 1.0 hour for throttle body replacement and relearn procedure if required (total estimated shop time: 1.5 – 3.0 hours).