Diagnostic Instructions
DTC Descriptors
DTC P0705: Transmission Range (TR) Switch Circuit
Circuit/System Description
The transmission range (TR) switch is part of the park/neutral position and back-up lamp switch assembly and is externally mounted on the transmission manual shaft. The TR switch is a multi-signal switch. The transmission control module (TCM)
supplies ignition voltage to the TR switch on 4 signal circuits, A, B, C, and P. Each gear selector lever position grounds 1 or more of the switch circuits. In order to determine the gear range selected by the driver, the TCM compares the voltage combinations
on the signal circuits to a look-up table stored in TCM memory. The TCM detects the selected gear range by the state change of the switch input. Refer to
Transmission Range Switch Logic
.
Switch input to the TCM is represented on the scan tool as HI and LOW. HI indicates an ignition voltage signal. LOW indicates a zero voltage signal. The 4 parameters represent transmission range switch signal A, B, C and Parity.
Conditions for Running the DTC
The engine run time is greater than 5 seconds and not in fuel cut-off.
Conditions for Setting the DTC
The combination of TR switch signals are invalid for 60 seconds. Refer to
Transmission Range Switch Logic
.
Action Taken When the DTC Sets
DTC P0705 is a type C DTC.
Conditions for Clearing the DTC
DTC P0705 is a type C DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
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
J 35616
GM-Approved Terminal Test Kit
Circuit/System Verification
Start the engine. With the vehicle in PARK and at normal operating temperature, observe the TR Sw. A/B/C/P parameter on the scan tool. The TR Sw. A/B/C/P parameter should display LOW/HIGH/HIGH/LOW.
Circuit/System Testing
- Turn ON the ignition, leaving the engine OFF. Using a scan tool, observe the TR Sw. parameter while selecting each transmission range. The TR Sw. parameter should match each range when selected.
⇒ | If the TR Sw. range on the scan tool matches each selected range, test for intermittent conditions. |
- Inspect the park/neutral position (PNP) switch assembly and the shift cable for the following conditions:
⇒ | If any of the conditions are found, repair or replace as necessary. |
• | Loose or missing mounting hardware |
• | Damaged or stretched cable |
- Using the scan tool, observe the TR Sw. A/B/C/P parameter. The parameter should display LOW/HIGH/HIGH/LOW.
⇒ | If the scan tool displays HI for all signal states, repair the open or high resistance in the ground circuit for the PNP switch. |
- Turn OFF the ignition. Disconnect the PNP switch connector. Turn ON the ignition, leaving the engine OFF. Observe the TR Sw. A/B/C/P parameter on the scan tool. The scan tool should display HI for all TR Sw. signal circuits.
⇒ | If any of the TR Sw. A/B/C/P signal circuits do not display HI, test the affected circuit for a short to ground. |
- Using the
J 35616
GM-approved terminal test kit and a DMM, measure the voltage at each TR signal circuit to ground. Each circuit should measure 10-12 volts.
⇒ | If the voltage on any of the circuits is less than the specified value, test the affected circuit for an open or high resistance. |
⇒ | If an open or high resistance is not found, replace the TCM. |
- Turn OFF the ignition. Leaving the PNP switch disconnected, disconnect the TCM harness connector. Using the
J 35616
, measure the resistance between each TR signal circuit and all other TR signal
circuits. The resistance should be greater than 10K ohms.
⇒ | If the resistance is less than 10K ohms, test for a shorted together condition on the TR signal circuits. |
⇒ | If all circuits and connections test normal, test the PNP switch. |
Component Testing
Using the
J 35616
, connect a test lamp between battery positive voltage and any of the TR signal circuits at the PNP switch. Referring to
Transmission Range Switch Logic
will ensure that the test lamp illuminates when the TR signal circuit that is being tested is grounded.
⇒ | If the test lamp does not illuminate when the circuit is grounded, replace the PNP switch. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Ensure the TR. Sw. A/B/C/P parameter on the scan tool displays a valid range for all ranges selected for 5 seconds.
Park/Neutral Position Switch Replacement
Control Module References
for TCM replacement, setup, and programming
Transmission Wiring Harness Removal