Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0815: Upshift Switch CircuitDTC P0816: Downshift Switch Circuit
Diagnostic Fault Information
Driver Shift Request
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
Tap Upshift Switch | -- | -- | P0815 |
Tap Downshift Switch | -- | -- | P0816 |
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
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
Connector End View Reference
Description and Operation
Transmission General Description
Electrical Information Reference
| • | Circuit Testing |
| • | Wiring Repairs |
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Transmission Control Module Scan Tool Information
Circuit/System Verification
- Ignition ON, transmission shift lever in D (+/-), observe the scan tool Driver Shift Request parameter. The reading should display None.
- Observe the scan tool Driver Shift Request parameter while pressing the tap-up and tap-down switch. The reading should change between Upshift and Downshift.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the transmission shift lever.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.
- Verify the scan tool Driver Shift Request parameter indicates Invalid.
- Ignition OFF, test for 300-600 ohms between the signal circuit terminal B and ground.
- If all circuits test normal, test or replace the TCM.
| ⇒ | If the test lamp does not illuminate, test the IGN circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If other than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the transmission control.
- Test for 8.1-8.4 K ohms between terminals A and B.
- Test for 2.6-3.2 K ohms between terminals A and B while pressing the upshift button.
- Test for 1.0-1.6 K ohms between terminals A and B while pressing the downshift button.
| ⇒ | If not within the specified range, replace the transmission control. |
| ⇒ | If not within the specified range, replace the transmission control. |
| ⇒ | If not within the specified range, replace the transmission control. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Replace the AT shift switch. Refer to Transmission Control Replacement. |
| • | Replace the control solenoid (w/body and TCM) valve assembly. Refer to Control Module References for replacement, setup, and programming. |
