5L40-E/5L50-E - Automatic Transmission
DTC P0815 or P816
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0815
- Upshift Switch Circuit
DTC P0816
- Downshift Switch Circuit
Circuit/System Description
The TAP Shift system allows the driver to manually shift gears by using the Upshift and Downshift positions located on the automatic transmission shift Lever. Pushing the lever to the Upshift position will command an upshift and pushing the lever to the Downshift position will command a downshift. The TAP Shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.
Conditions for Running the DTC
P0815
* No Tap up/ Tap down DTC P0826.
* No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
* The engine run time is greater than 5 seconds.
* The time since last gear selector range change is greater than 6 seconds.
P0816
* No Tap up/ Tap down DTC P0826.
* No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
* The engine run time is greater than 5 seconds.
* The time since last gear selector range change is greater than 6 seconds.
Conditions for Setting the DTC
P0815
The TCM detects an upshift request for 2 seconds in PARK or for 600 seconds.
P0816
The TCM detects a downshift request for 2 seconds in PARK or for 600 seconds.
Action Taken When the DTC Sets
P0815
The TCM disables TAP Shift operation.
P0816
The TCM disables TAP Shift operation.
Conditions for Clearing the DTC
DTCs P0815 and P0816 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Transmission General Description (Transmission General Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Transmission Control Module Scan Tool Information (5L40-E) (Transmission Control Module Scan Tool Information (5L40-E))Transmission Control Module Scan Tool Information (6L50/6L80/6L90) (Transmission Control Module Scan Tool Information (6L50/6L80/6L90))
Circuit/System Testing
P0815
1. Select the Driver Shift Request parameter.
2. Disconnect the automatic transmission (AT) TAP shift switch connector.
• If the parameter status changes from Upshift to Invalid, replace the AT TAP shift switch.
• If the parameter status does not change, check ignition 1 voltage circuit, if no trouble found, replace TCM.
P0816
1. Select the Driver Shift Request parameter.
2. Disconnect the automatic transmission (AT) TAP shift switch connector.
• If the parameter status changes from Downshift to Invalid, replace the AT TAP shift switch.
• If the parameter status does not change, check ignition 1 voltage circuit, if no trouble found, replace TCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Replace the AT shift switch. Refer to Transmission Control Replacement (Left Hand Drive) (Transmission Control Replacement (Left Hand Drive))Transmission Control Replacement (Right Hand Drive) (Transmission Control Replacement (Right Hand Drive)) .
* Replace the control solenoid (w/body and TCM) valve assembly. Refer to Control Module References (Programming and Relearning) for replacement, setup, and programming.