2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2334
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 11-18 volts.
* Engine Speed is 1000 RPM or greater.
* TP is 8 percent or greater.
* Engine torque is 75 Nm (55 lb ft) or greater.
* Vehicle speed is 10 km/h (6 mph) or greater.
Conditions for Setting the DTC
P0850 or P0851
The ECM detects the Park/Neutral switch signal equals 0 volts, Low, when the IMS reports a Drive range.
P0852
The ECM detects the Park/Neutral switch signal equals 12 volts, High, when the IMS reports a Park/Neutral range.
Action Taken When the DTC Sets
* DTC P0850, P0851, and P0852 are Type C DTCs.
* The ECM uses IMS Range for engine start-up.
Conditions for Clearing the DTC
DTC P0850, P0851, and P0852 are Type C DTCs.
Reference Information
Schematic Reference
* Automatic Transmission Controls Schematics (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)
