DTC P0850-P0852
Diagnostic Instructions
DTC Descriptors
DTC P0850: Park/Neutral Position Switch Circuit
DTC P0851: Park/Neutral Position Switch Circuit
Low Voltage
DTC P0852: Park/Neutral Position Switch Circuit
High Voltage
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Park/Neutral Signal
|
P0850/P0851
|
P0850/P0852
|
P0850/P0852
|
--
|
Typical Scan Tool Data
PNP Switch
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Operating Conditions: Engine running,
normal operating temperature
Parameter Normal Range: 12 Volts
= In-Gear, 0 Volts = Park/Neutral
|
Park/Neutral Signal
|
Park/Neutral
|
In-Gear
|
In-Gear
|
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 park/neutral signal
circuit uses the TCM as a pass-through connector only. The TCM
provides the low reference circuit to the PNP switch.
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
• |
The ignition voltage is between
8-18 volts. |
• |
The 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. |
• |
The throttle position is 10 percent or
greater. |
• |
The engine torque is 75 N·m
(55 lb ft) or greater. |
• |
The vehicle speed is 10 km/h (6 mph) or
greater. |
P0852
The ECM detects the Park/Neutral switch signal equals
12 volts (In-Gear) when the IMS reports a Park/Neutral range
for 0.2 second.
Action Taken When the DTC Sets
• |
DTCs P0850, P0851, and P0852 are
Type C DTCs. |
• |
The ECM uses IMS Range for engine start-up. |
Conditions for Clearing the DTC
DTCs P0850, P0851, and P0852 are Type C DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Electronic Component Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
DT-48616-10 Adapter Harness
For equivalent regional tools, refer to
Special Tools .
Circuit/System Verification
- If there are any other transmission DTCs set, diagnose
those DTCs first. Refer to
Diagnostic Trouble Code (DTC) List - Vehicle .
- Ignition ON, observe the scan tool ECM Park/Neutral
Position Switch parameter while moving the gear shift lever from
Park and through all ranges. The parameter should display
Park/Neutral when in Park or Neutral and In-Gear when in Reverse or
Drive.
- Observe the scan tool TCM Internal Mode Switch
parameter while slowly moving the gear shift lever from Park
through all ranges. Verify the gear shift lever position matches
the scan tool Internal Mode Switch parameter.
- After performing the above steps, verify that the DTC
does not reset by operating the vehicle within the Conditions for
Running the DTC. You may also operate the vehicle within the
conditions you observe from the Freeze Frame/Failure Records data.
If the vehicle passes the Circuit/System Verification procedure,
then STOP. Do not perform the Circuit/System Testing or Component
Testing as this may result in an unnecessary part replacement.
Refer to
Testing for Intermittent Conditions and Poor Connections .
Circuit/System Testing
Note: You must perform the
Circuit/System Verification first.
- Ignition OFF, disconnect the X1 14-way harness
connector at the transmission.
- Install the DT-48616-10 harness to the
vehicle wire harness X1 14-way transmission connector.
- Test for less than 10 ohms between the ground
circuit terminal 2 and ground.
⇒ |
If greater than the specified range, test the
ground circuit for an open/high resistance. |
- Ignition ON, engine OFF, test for 11-13 volts
between the adaptor harness terminal 3 and ground.
⇒ |
If not within the specified range, test the signal
circuit for a short-circuit to ground or an open/high resistance.
If the circuit tests normal, replace the K20 ECM. |
- Ignition OFF, disconnect the DT-48616-10
harness from the vehicle wire harness X1 14-way transmission
connector.
- Remove the transmission control valve body cover.
Refer to
Control Valve Body Cover Replacement .
- Connect the vehicle wire harness X1 14-way
transmission connector to the Q8 control solenoid valve
assembly.
- Disconnect the B15 transmission internal mode switch
electrical X2 connector from the Q8 control solenoid valve
assembly.
- Ignition ON, test for 11-13 volts between
terminal A on the X2 connector at the Q8 control solenoid
valve assembly and ground at the transmission case.
⇒ |
If not within the specified range, replace the Q8
control solenoid valve assembly. |
- Connect a 3A fused jumper wire between the X2
connector terminal A and ground. Verify with a scan tool the
Park/Neutral Position Switch parameter changes from In Gear to
Park/Neutral when connected to ground.
⇒ |
If not the expected results, test the signal
circuit for an open/high resistance or a short-circuit to ground or
voltage. If circuit tests normal, replace the K20 ECM. |
- If all circuits test normal, replace the B15
transmission internal mode switch.
Repair Instructions
Note:
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|