šØ Diagnostic Profile
Vehicle/Equipment Make: BUICK
Technical Description: Cruise Control System Vehicle Acceleration Too High
This diagnostic code indicates that the vehicle’s actual acceleration rate exceeds the expected threshold commanded by the cruise control module. This typically points to a discrepancy between the throttle actuator commands and the resulting wheel speed/acceleration sensor feedback, often caused by a sticking throttle body, faulty accelerator pedal position (APP) sensor, or a malfunctioning Powertrain Control Module (PCM) relationship with the cruise control module.
šØ Repair Difficulty Tier
Rating: Intermediate
This repair requires a diagnostic scan tool capable of reading live PCM and cruise control data streams, along with knowledge of throttle body mechanics and sensor calibration. While not requiring CAN bus module flashing in most cases, it does require intermediate electrical diagnostic skills, including the use of a multimeter to verify sensor voltage outputs and circuit continuity. A professional-grade scan tool (not just a basic code reader) is strongly recommended for accurate live data interpretation.
š ļø Resolution Steps
Step 1: Preliminary Inspection
Begin by visually inspecting the throttle body for carbon buildup, binding, or mechanical obstruction that could cause erratic throttle response. Check the accelerator pedal assembly for smooth, unobstructed movement. Inspect all electrical connectors at the Throttle Position Sensor (TPS), Accelerator Pedal Position (APP) sensor, and cruise control module for corrosion, loose pins, or damaged wiring harnesses. Verify the cruise control engagement/disengagement switches on the steering wheel are functioning mechanically without sticking.
Step 2: Diagnostic Verification
Connect a professional-grade scan tool to the OBD-II port and access live data streams for the following parameters: Accelerator Pedal Position (APP), Throttle Position (TP), Vehicle Speed Sensor (VSS), and Commanded Throttle Angle. Compare the commanded throttle angle against actual throttle position while road testing with cruise control engaged ā any significant lag or deviation points to a mechanical or sensor fault. Use a digital multimeter to check APP sensor output voltage (typically 0.5Vā4.5V range) at idle and during simulated acceleration. Check for any stored freeze frame data correlating to the acceleration fault, and test the throttle actuator control (TAC) module circuit resistance per OEM specifications.
Step 3: Resolution & Reset Process
If the throttle body shows contamination, perform a thorough cleaning using approved throttle body cleaner and allow the PCM to relearn idle parameters. If the APP or TPS sensor readings fall outside factory specifications, replace the faulty sensor assembly. After component replacement, use the scan tool to perform a Throttle Position Relearn Procedure and clear all stored Diagnostic Trouble Codes (DTCs). Conduct a final road test with cruise control engaged across varying speeds to confirm acceleration rates match commanded inputs smoothly without hesitation or surge.
š¦ Parts, Labor, and Budget Estimates
Required Components/Software: Throttle Position Sensor (TPS), Accelerator Pedal Position (APP) Sensor, Throttle Body Assembly (if contaminated/damaged), OEM-level diagnostic scan tool (e.g., GM Tech2 or equivalent aftermarket tool with bi-directional control)
Average Component Price: $85 ā $350 depending on sensor vs. full throttle body replacement; dealer-level diagnostic scan access typically included in standard shop diagnostic fee
Estimated Labor Hours: 1.5 ā 3.0 hours (includes diagnostic time, sensor/component replacement, and relearn procedure)