Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC P0985: Shift Solenoid Valve 1 Control Circuit Low VoltageDTC P0986: Shift Solenoid Valve 1 Control Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Shift Solenoid Control | P0985 | P0986 | P0986 | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: On / Off | |||
Shift Solenoid Control | Off | Off | Off |
Circuit/System Description
Shift Solenoid Valve 1 (S1) is installed on the middle valve body. The solenoid turns ON and OFF in response to signals output from the TCM. According to the ON or OFF status of S1 or S2, the 1st gear engine brake operates or the gear shifts into change. As a fail-safe function, if any shift solenoid abnormality occurs, the TCM will disable the current to the solenoids.
Conditions for Running the DTC
P0985
| • | The ignition voltage is between 10.2 V and 15.5 V. |
| • | The engine speed is greater than 400 RPM for 2 seconds. |
| • | The transmission is not in emergency mode. |
| • | 10 ms after solenoid output changed. |
P0986
| • | The ignition voltage is between 10.2 V and 15.5 V. |
| • | The engine speed is greater than 400 RPM for 2 seconds. |
| • | The transmission is not in emergency mode. |
| • | 10 ms after solenoid output changed. |
Conditions for Setting the DTC
P0985
The TCM detects an ON signal (12 V) of the S 1 circuit when the S 1 is commanded OFF (0 V) for 100 ms continuously after 5 times.
P0986
The TCM detects an OFF signal (0 V) of the S 1 circuit when the S 1 is commanded ON (12 V) for 100 ms continuously after 5 times.
Action Taken When the DTC Sets
| • | DTCs P0985 and P0986 are Type A DTCs. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM turns OFF all solenoids. |
| • | The TCM allows the vehicle to operate only in the second gear and "R" range after a stop. |
Conditions for Clearing the DIC/DTC
| • | DTCs P0985 and P0986 are Type A DTCs. |
| • | The TCM detects an ON signal (12 V) of the S 1 circuit when the S 1 is commanded ON (12 V) for 1 s continuously. |
| • | The TCM detects an OFF signal (0 V) of the S 1 circuit when the S 1 is commanded OFF (0 V) for 1 s continuously. |
Diagnostic Aids
When attempting to set solenoid electrical DTCs, ensure the control solenoid valve assembly is warmed up and the transmission is operated long enough to ensure a 3°C (5°F) increase in temperature. This will place the TCM in the optimal conditions to test solenoid electrical DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
Description and Operation
Transmission Component and System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ensure the transmission fluid temperature is between 50 to 80°C (122 to 176°F).
- Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in oil temperature.
- Place the gear selector in Reverse for 5 s and then idle vehicle for 5 s.
- Observe the scan tool data parameter Shift Solenoid Valve 1. The parameter should display ON.
Circuit/System Testing
Static Test
- Ignition OFF, remove the K71 Transmission Control Module (TCM).
- Test for 11-15 Ω between the Shift Solenoid Control circuit terminal 5 (X2) and ground.
- Test for infinite resistance between each terminal and the Shift Solenoid Control circuit terminal 5 (X2).
- If all circuits test normal, test or replace the Q32A Shift Solenoid (SS) Valve. Verify the DTC does not reset.
| ⇒ | If not within the specified range, test the wiring harness for internal short, or interruption. If the circuit test normal, replace the Q32A Shift Solenoid (SS) Valve. |
| ⇒ | If less than the specified range, replace the wiring harness. |
| ⇒ | If the DTC resets, replace the K71 Transmission Control Module (TCM). |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control valve body replacement. Refer to Control Valve Body Replacement for replacement, setup and programming. |
| • | TCM, refer to Control Module References for replacement, setup and programming. |
| ⇒ | Perform the Transmission Adaptive Functions. |
| • | Wiring harness, refer to Automatic Transmission Wiring Harness Replacement for replacement |
