2010 Cadillac CTS Sedan AWD V6-3.6L Page 1758
* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and
Inspection/Programming and Relearning/Service Fast Learn Adapts) following all transmission related repairs.
P0990
DTC P0989 or P0990
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 P0989
- Transmission Fluid Pressure (TFP) Switch 5 Circuit Low Voltage
DTC P0990
- Transmission Fluid Pressure (TFP) Switch 5 Circuit High Voltage
Diagnostic Fault Information
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.
