2010 Cadillac Truck SRX FWD V6-3.0L Page 1771
* 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 control solenoid valve assembly replacement, setup, or
programming
P0850
DTC P0850-P0852
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 P0850
- Park/Neutral Position (PNP) Switch Circuit
DTC P0851
- Park/Neutral Position (PNP) Switch Circuit Low Voltage
DTC P0852
- Park/Neutral Position (PNP) Switch Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The transmission manual shift shaft switch assembly, also known as the Internal Mode Switch (IMS), is a sliding contact switch attached to the
manual shift shaft inside the transmission case. The Park/Neutral Position (PNP) Switch is integrated into the IMS and connects to the Transmission
Control Module (TCM) lead-frame through a short wire harness. The circuit uses the TCM as a pass-through connector only. The Park/Neutral
Signal is sent from the park/neutral switch directly to the engine control module (ECM) and is used for engine start enable.
Conditions for Running the DTC
* Ignition voltage is between 8-18 volts.
* Engine speed is greater than 1000 RPM.
Conditions for Setting the DTC
P0850 and P0851
* The ECM detects the Park/Neutral switch signal equals 0 volts (Park/Neutral) when the IMS reports a Drive range for 0.2 second.
* TP is equal to or greater than 10 percent.
* Engine torque is equal to or greater than 75 Nm (55 lb ft).
* Vehicle speed is equal or greater than 10 km/h (6 mph).
