2010 Cadillac CTS Sedan AWD V6-3.0L Page 1688

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1688

DTC P0873

- Transmission Fluid Pressure (TFP) Switch 3 Circuit High Voltage

Diagnostic Fault Information

Typical Scan Tool Data

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 is exhausted through the 2-6 clutch regulator valve.

Conditions for Running the DTC

P0872 or P0873

* DTCs P0711, P0712, P0713, P0973, P0974, P0976, P0977, P1915, or P182E are not set.

* Ignition voltage is 8.6 volts or greater.

* The transmission fluid temperature (TFT) is 0-120掳C (32-248掳F).

* Engine speed is 500 RPM or greater for 5 seconds.

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 20 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 18 counts are accumulated.

Action Taken When the DTC Sets

* DTCs P0872 and P0873 are Type C DTCs.

* The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

DTCs P0872 and P0873 are Type C DTCs.

Diagnostic Aids

A TFP switch may malfunction due to normal debris in the transmission fluid causing a TFP Switch DTC to intermittently set. This type of

condition should not be immediately noticeable to a customer, as the switch outputs are used for shift adaptive pressure and do not cause

transmission symptoms unless the switch malfunctions continuously for an extended period of time.