The P2788: Auto Shift Manual Adaptive Learning at Limit code indicates that the adaptive learning system for the automatic shift manual transmission has reached its operational limits. This means that the transmission control module can no longer compensate for variations and requires recalibration or adjustments. This could be due to a faulty control module, learning parameters that have been exceeded, or issues with the system calibration.
P2788 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P2788: Auto Shift Manual Adaptive Learning at Limit |
| Is it serious? | Yes, if the adaptive learning has reached its limit, the transmission may experience shifting issues, poor performance, or erratic behavior, which could eventually lead to transmission damage. |
| Possible causes | – Adaptive learning for auto shift manual is at its limit – Faulty control module – Learning parameters exceeded |
| How to diagnose? | – Verify adaptive learning parameters – Inspect control module for faults – Check learning and calibration procedures – Perform recalibration or replace components as needed |
P2788 Meaning
The P2788: Auto Shift Manual Adaptive Learning at Limit code indicates that the adaptive learning function of the automatic shift manual transmission has reached its maximum allowable adjustments. The transmission control module (TCM) uses adaptive learning to optimize shift quality by adjusting for wear and changes in transmission characteristics over time. When it reaches the limits of its adjustments, it suggests there are mechanical issues that exceed what the control system can compensate for, or the TCM itself might be malfunctioning.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to determine if there are any other related transmission or control module codes present. Additional codes may help identify the specific area that is preventing the adaptive learning from functioning properly. | OBD-II Scanner |
| Verify Adaptive Learning Parameters | Use a diagnostic tool to access and check the current adaptive learning parameters in the transmission control module. Compare these values against the manufacturer’s specifications to determine if they have reached or exceeded allowable limits. | Diagnostic Tool, Manufacturer Specifications |
| Inspect Control Module for Faults | Perform a visual inspection of the control module and related connectors for any signs of damage, corrosion, or loose connections. Use a diagnostic tool to check for faults or anomalies in the TCM operation. If the TCM is malfunctioning, it may not be able to adapt properly, causing this code to set. | Diagnostic Tool, Flashlight, Multimeter |
| Check Learning and Calibration Procedures | Consult the vehicle’s manual or service documentation to understand the calibration procedure for the adaptive learning system. Verify if the learning has been interrupted or if there has been a calibration error. Re-perform the calibration if required. | Manufacturer Service Manual |
| Relearn or Recalibrate the Transmission | Use a diagnostic tool to initiate a relearn or recalibration process for the transmission. This will allow the TCM to reset its adaptive parameters and start learning again from the base settings. This step may resolve the issue if it is related to exceeded learning parameters. | Diagnostic Tool, Manufacturer Software |
| Perform Transmission Service | Inspect the transmission fluid level and quality. Old or degraded transmission fluid can lead to poor performance that the control module cannot adapt to. Replace the fluid if it is discolored or contaminated. Proper lubrication is critical for smooth shifting and adaptive learning. | Transmission Fluid Dipstick, Transmission Fluid Replacement Tools |
| Check for Mechanical Issues | Inspect the transmission for any mechanical issues such as excessive clutch wear, solenoid issues, or actuator problems. If the transmission has mechanical wear beyond what the TCM can adapt to, parts like clutches or solenoids may need replacement. | Flashlight, Safety Gloves, Diagnostic Tool |
| Replace Faulty Control Module or Components as Needed | If the control module is determined to be faulty, consider repairing or replacing it. Ensure all new components meet manufacturer specifications and that all connections are secure before reinstallation. | Replacement Control Module, Wiring Repair Kit |
| Clear the Code and Test Drive | After completing the necessary repairs or recalibration, use an OBD-II scanner to clear the P2788 code. Take the vehicle for a test drive and monitor transmission behavior to ensure that adaptive learning is functioning properly without reaching its limits again. | OBD-II Scanner |
| Recheck for Codes | Perform a final scan after the test drive to confirm that the P2788 code has not returned. If the code persists, further diagnostics may be required to determine the root cause of the issue. | OBD-II Scanner |
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