The drivers shift request (DSR), also known as the TAP Shift, allows the driver to manually shift gears by pressing the plus (+) or minus (-) buttons and select the desired range of gears for current driving conditions by using the DSR shift switch located on the automatic transmission gear shift lever. Pushing the plus (+) switch will command an upshift and pushing the minus (-) switch will command a downshift. A 12 V reference voltage flows from the body control module (BCM) through the DSR switch resistor array to the BCM. The DSR shift system is activated when the gear selector is in the Manual (M) position. The DSR system is deactivated in all other range positions.

P0815, P0816, or P0826

The engine speed is between 200-7500 RPM for at least 5 seconds.

P0815 or P0816

P0815

The BCM detects an upshift request for 3 seconds in PARK, REVERSE, NEUTRAL, or D1 and for 600 seconds in PARK, REVERSE, NEUTRAL, D2, or D1.

P0816

The BCM detects a downshift request for 3 seconds in PARK, REVERSE, NEUTRAL, or D1 and for 600 seconds in PARK, REVERSE, NEUTRAL, D2, or D1.

P0826

The BCM detects an invalid voltage on the TAP up/down signal circuit for 5 seconds.

DTCs P0815, P0816, P0826, and P1876 are Type C DTCs.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify with a scan tool the Tap Up/Down Switch parameter displays On.
2. Ignition ON, cycle the automatic transmission manual shift switch while observing the Tap Up/Down Switch parameter. The parameter should change to Up when the plus (+) switch is selected, and Down when the minus (-) switch is selected.
3. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

1. Ignition OFF, disconnect the automatic transmission shift lever harness connector.
2. Ignition ON, verify with a scan tool the Tap Up/Down Switch parameter displays Off.

⇒	If not the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.

3. Ignition ON, test for greater than 11 V between the ignition voltage circuit terminal D and ground.

⇒	If less than the specified value, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Ignition OFF, test for 6.6-7.0 K ohms between terminal C and terminal D of the automatic transmission shift lever harness connector. Also, test for 3.7-4.2 K ohms when selecting the minus (-) switch, and 1.7-2.0 K ohms when selecting the plus (+) switch.

⇒	If not within the specified values, replace the automatic transmission lever.

⇒	If the specified values are normal, test the signal circuit for a short to ground or an open/high resistance. If circuit tests normal, replace the BCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.