2010 Cadillac CTS Sedan AWD V6-3.6L Page 1756
Typical Scan Tool Data
Circuit/System Description
The transmission fluid pressure (TFP) switch 5 is part of the control solenoid valve assembly which has no serviceable parts. The TCM supplies a
signal circuit to the TFP switch 5. The TFP switch 5 has an internal case ground. TFP switch 5 is normally closed or LOW. When oil pressure is
present at the TFP switch 5, the switch is open or HIGH. The normally high pressure control (PC) solenoid 3 controls pressure to the CBR1/4-5-6
clutch regular valve. The TCM monitors the TFP switch 5 signal circuit to determine the position of the CBR1/4-5-6 clutch regulator valve. When
the 4-5-6 clutch is commanded OFF, pressure is present on the TFP switch 5. When the 4-5-6 clutch is commanded ON, the CBR1/4-5-6 clutch
regulator valve moves and pressure to the TFP switch 5 is exhausted through the CBR1/4-5-6 clutch regulator valve.
Conditions for Running the DTC
P0989 or P0990
* 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
P0989
The TCM detects that the TFP switch 5 signal voltage remains LOW after the 4-5-6 clutch transitions from a HIGH pressure state to a LOW
pressure state. The TCM counts each incident. The DTC sets when 15 counts are accumulated.
P0990
The TCM detects that the TFP switch 5 signal voltage remains HIGH after the 4-5-6 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 P0989 and P0990 are Type C DTCs.
* The TCM freezes transmission adaptive functions.
Conditions for Clearing the DTC
DTCs P0989 and P0990 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.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)
Connector End View Reference
