2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1660
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0815
- Upshift Switch Circuit
DTC P0816
- Downshift Switch Circuit
DTC P0826
- Up and Down Shift Switch Circuit
Diagnostic Fault Information
Circuit/System Description
When the shift lever is placed in manual mode (M) this activates the driver shift request (DSR), also known as the tap shift function. The DSR
allows the vehicle operator to shift gears by pressing the plus (+) button for an upshift or the minus (-) button for a downshift. A 12 volt signal
circuit is provided by the body control module (BCM) to the plus or minus buttons. When a plus or minus button is pressed, a corresponding
voltage drop occurs across the resistor network embedded in the switches. This voltage drop is monitored by the transmission control module
(TCM). The TCM will command the upshift or downshift providing the operating conditions are correct.
Conditions for Running the DTC
P0815 or P0816
* No DTCs P0815, P0816, P0826, P1761, P182E, P1876, P1877, or P1915.
* The time since the range change is greater than 1 second.
* The engine speed is 400 RPM or greater for 5 seconds.
* The ignition voltage is 8.6 volts or greater.
P0826
* The engine speed is greater than 400 RPM for at least 5 seconds.
* The ignition voltage is 8.6 volts or greater.
* No DTC 1761.
Conditions for Setting the DTC
P0815 - Condition 1
The TCM detects an upshift request for 1 second in PARK or neutral.
P0815 - Condition 2
The TCM detects an upshift request for 10 minutes in any forward range.
P0816 - Condition 1
* The TCM detects a downshift request for 1 second in PARK or neutral.
* The TCM detects a downshift request for 10 minutes in any forward range.
P0826
The TCM detects an invalid voltage on the TAP up/down signal circuit for 1 minute.
