• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
TR Signal A | P0705 | P0705 | -- | -- |
TR Signal B | P0705 | P0705 | -- | -- |
TR Signal C | P0705 | P0705 | -- | -- |
TR Signal P | P0705 | P0705 | -- | -- |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine running in Park, normal operating temperature Parameter Normal Range: HI when switch open, LOW when switch grounded. | |||
TR Sw. A/B/C/P | LOW | HI | -- |
The transmission range (TR) switch is part of the Park/Neutral Position (PNP) switch and is 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 one or more of the signal circuits in a unique pattern. In order to determine the gear range selected by the driver, the TCM compares the voltage combination on the signal circuits to a TR switch combination table stored in memory. Refer to Transmission Range Switch Logic .
The engine is running for 5 seconds.
The combination of TR switch signals is invalid for 60 seconds. Refer to Transmission Range Switch Logic .
• | DTC P0705 is a type C DTC. |
• | The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting. |
DTC P0705 is a type C DTC.
Automatic Transmission Controls Schematics
• | J 35616 GM Terminal Test Kit |
• | J 44152 Jumper Harness (20 pins) |
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.
⇒ | If the TR Sw. range on the scan tool matches each selected range, test for intermittent conditions. |
⇒ | If any of the conditions are found, repair or replace as necessary. |
• | Damage |
• | Loose or missing mounting hardware |
• | Proper adjustment--refer to Park/Neutral Position Switch Replacement |
• | Damaged or stretched cable |
• | Proper adjustment |
⇒ | If the scan tool displays HI for all signal states, repair the open or high resistance in the ground circuit for the PNP switch. |
⇒ | 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. |
⇒ | 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. |
⇒ | 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. |
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. |
Perform the Diagnostic Repair Verification after completing the repair.
• | Ensure that the TR. Sw. A/B/C/P parameter on the scan tool displays a valid range for all ranges selected for 5 seconds. |
• | Control Module References for TCM replacement, setup, and programming. |