2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1680
programming
P0873
DTC P0872 or P0873
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 P0872
- Transmission Fluid Pressure (TFP) Switch 3 Circuit Low Voltage
DTC P0873
- Transmission Fluid Pressure (TFP) Switch 3 Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The transmission fluid pressure (TFP) switch 3 is part of the control solenoid valve assembly, which has no serviceable parts. The TCM supplies a
signal circuit to the TFP switch 3. The TFP switch 3 has an internal case ground. TFP switch 3 is normally closed or LOW. When oil pressure is
present at the TFP switch 3, the switch is open or HIGH. The normally low clutch pressure control (PC) solenoid 4 controls pressure to the 2-6
clutch regulator valve. The TCM monitors the TFP switch 3 to determine the position of the 2-6 clutch regulator valve. When the 2-6 clutch is
commanded OFF, pressure is present on the TFP switch 3. When the 2-6 clutch is commanded ON, the 2-6 clutch regulator valve moves and
pressure to the TFP switch 3 is exhausted through the 2-6 clutch regulator valve.
Conditions for Running the DTC
P0872 or P0873
* No DTCs P0711, P0712, P0713, P0716, P0717, P0722, P0723, P0742, P0751, P0756, P0757, P0973, P0974, P0976, P0977, P1915, or
P182E.
* The high side driver is on.
* The engine speed is 400 RPM or greater for 5 seconds.
* The engine speed is 550 RPM or greater.
* Ignition voltage is 8.6 volts or greater.
* The transmission fluid temperature (TFT) is 0-120掳C (32-248掳F).
Conditions for Setting the DTC
P0872
The TCM detects that the TFP switch 3 signal voltage remains LOW after the 2-6 clutch transitions from a HIGH pressure state to a LOW pressure
state. The TCM counts each incident. The DTC sets when 18 counts are accumulated.
P0873
The TCM detects that the TFP switch 3 signal voltage remains HIGH after the 2-6 clutch transitions from a LOW pressure state to a HIGH pressure
state. The TCM counts each incident. The DTC sets when 20 counts are accumulated.
Action Taken When the DTC Sets
* DTCs P0872 and P0873 are Type C DTCs.
* The TCM freezes transmission adaptive functions for the 2-6 clutch.
