🚨 Diagnostic Profile
Make: BUICK
Technical Description: TP Sensor Learned CI
This code/status indicates that the Throttle Position (TP) Sensor value has been successfully learned and stored by the Engine Control Module (ECM) as the new baseline reference point. This typically occurs after a throttle body replacement, ECM reflash, or battery disconnect, where the module recalibrates the minimum (closed) throttle position to ensure accurate airflow and idle calculations.
🚨 Repair Difficulty Tier
Tier: Intermediate
While reading the ‘Learned’ status itself is simple, verifying that the learn procedure was successful and correcting it if it failed requires a capable scan tool (such as GM Tech 2 or a bidirectional aftermarket scanner) capable of reading live Parameter IDs (PIDs) and performing relearn procedures. Basic hand tools are sufficient for physical inspection, but electronic verification requires intermediate diagnostic equipment.
🛠️ Resolution Steps
Step 1: Preliminary Inspection
Visually inspect the throttle body for carbon buildup, debris, or physical damage to the throttle plate that could prevent it from fully closing to its mechanical stop. Check the electrical connector at the throttle body for corrosion, bent pins, or loose connections. Inspect the wiring harness for chafing or damage between the throttle body and the ECM.
Step 2: Diagnostic Verification
Connect a scan tool and navigate to the ECM data stream. Monitor the TP Sensor Percentage (%) and TP Sensor Volts PIDs with the key on, engine off. At idle (closed throttle), voltage should typically read between 0.5V–1.0V (varies by model), with 0% throttle angle indicated. Compare live data against the factory-learned minimum value to confirm the sensor is reporting accurately and has not drifted out of range.
Step 3: Resolution & Reset Process
If the TP sensor has been successfully learned and values are within specification, no further action is required—this is a normal confirmation message, not a fault code. If values are erratic or the learn failed, perform the following: 1) Clear any stored DTCs. 2) Use the scan tool’s bidirectional controls to initiate a Throttle Body Relearn/Reset Procedure. 3) Turn the ignition off for 30 seconds to allow the ECM to power down fully. 4) Restart the vehicle and allow it to idle for 2–3 minutes, verifying stable idle RPM and no stored codes return.
📦 Parts, Labor, and Budget Estimates
Required Components/Software: OEM or quality aftermarket Throttle Body Assembly (if replacement is needed), GM-specific bidirectional scan tool (Tech 2, Tech 3, or equivalent aftermarket tool with relearn capability), electrical contact cleaner.
Average Component Price: $120 – $350 for a new throttle body assembly (parts only, varies by model). No additional software cost if using existing bidirectional scan tool; dealer-level relearn procedures are typically included in standard diagnostic service.
Estimated Labor Hours: 0.5 – 1.0 hour for diagnostic verification and relearn procedure only. If throttle body replacement is required, add 0.8 – 1.5 hours for removal, installation, and relearn confirmation (total estimated labor: 1.3 – 2.5 hours).