2010 Cadillac Truck SRX FWD V6-3.0L Page 1766
瀚慖f not the specified value, replace the left automatic transmission manual shift switch.
5. Test for open circuit on the left automatic transmission manual shift switch harness connector between terminals 1 and 2 and between
terminals 2 and 3. Test for less than 10 ohms between terminals 1 and 2 when the right automatic transmission manual shift tap down (-)
switch is pressed and between terminals 2 and 3 when the Tap Up (+) switch is pressed.
瀚慖f not the expected results, test the circuits between the left and right automatic transmission manual shift switch for an open/high
resistance or short to ground. If circuits test normal, replace the right automatic transmission manual shift switch.
6. If all circuits test normal, test or replace the transmission control.
Repair Instructions
Important:
* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and
Inspection/Programming and Relearning) following all transmission related repairs.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (See:
Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and Inspection/Component Tests and General
Diagnostics/6T70/6T75 - Automatic Transmission/Control Solenoid Valve and Transmission Control Module Assembly Inspection)
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Control Module References (See: Testing and Inspection/Programming and Relearning) for body control module (BCM) or control solenoid
valve assembly replacement, setup and programming
* Transmission Control Replacement (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Shifter A/T/Service and
Repair/6T70/6T75 - Automatic Transmission/Transmission Control Replacement)
P0842
DTC P0842 or P0843
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 P0842
- Transmission Fluid Pressure (TFP) Switch 1 Circuit Low Voltage
DTC P0843
- Transmission Fluid Pressure (TFP) Switch 1 Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The transmission fluid pressure (TFP) switch 1 is part of the control solenoid valve assembly, which has no serviceable parts. The TCM supplies a
signal circuit to the TFP Switch 1. The TFP Switch 1 has an internal case ground. TFP Switch 1 is normally closed or LOW. When oil pressure is
present at the TFP Switch 1, the switch is open or HIGH. The normally high clutch pressure control (PC) solenoid 2 controls pressure to the 3-5
reverse clutch regulator valve. The TCM monitors the TFP switch 1 to determine the position of the 3-5 reverse clutch regulator valve. When the
3-5 reverse clutch is commanded OFF, pressure is present on the TFP switch 1. When the 3-5 reverse clutch is commanded ON, the 3-5 reverse
clutch regulator valve moves and pressure to the TFP switch 1 is exhausted through the 3-5 reverse clutch regulator valve.
Conditions for Running the DTC
