vauxhall Workshop Repair Guides

Vauxhall Workshop Service and Repair Manuals

DTC P0731 > < DTC P0218

DTC P0778 or P0965-P0967

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 P0778: Pressure Control Solenoid Valve 1 System Performance
DTC P0965: Pressure Control Solenoid Valve 1 System Performance
DTC P0966: Pressure Control Solenoid Valve 1 Control Circuit Low Voltage
DTC P0967: Pressure Control Solenoid Valve 1 Control Circuit High Voltage

Diagnostic Fault Information



Circuit


Short to Ground


Open/High Resistance


Short to Voltage


Signal Performance


Signal


P0966


P0778, P0967


P0778, P0967


P0965


Low Reference


-


P0778, P0965, P0967


P0778, P0965, P0967


P0778, P0965, P0967

 

Typical Scan Tool Data


Pressure Control Solenoid Valve


Circuit


Short to Ground


Open


Short to Voltage



Operating Conditions: Engine running, normal operating temperature


Parameter Normal Range: 0.1-1.1 A


Signal


0 A


2.55 A


2.55 A


Low Reference


-


2.55 A


1


1. Internal TCM damage may occur if shorted to B+

 

Circuit/System Description

The shift control solenoid (SLC1) is installed on the front valve body. The solenoid linearly control hydraulic pressure in response to signals output from the transmission control module TCM. Through this, the SLC1 controls operating hydraulic pressure to the clutch 1 for smooth shifting. According to each shift control solenoid assembly, the transmission shifts from 1st gear into 6th gear and vice versa. As a fail-safe function, if any shift control solenoid assembly abnormality occurs, the TCM will disable the current to the solenoids.

Conditions for Running the DTC

P0778

•  The ignition voltage is between 10.2-15.5 V.
•  The engine speed is greater than 400 RPM for 2 s.
•  The transmission is not in emergency mode.
•  Driving in D range.
•  TCM communication is normal.
•  DTCs P0966 and P0967 are not set.

P0965

•  The ignition voltage is between 10.2-15.5 V.
•  The engine speed is greater than 400 RPM for 2 s.
•  The transmission is not in emergency mode.
•  Driving in D range.
•  TCM communication is normal.
•  The automatic transmission fluid temperature is more than 20°C (68°F).
•  SLC1 current is more than 0.85 A.
•  SLC1 target current is not changed.

P0966

•  The ignition voltage is between 10.2-15.5 V.
•  The engine speed is greater than 400 RPM for 2 s.
•  The transmission is not in emergency mode.
•  Driving in D range.
•  TCM communication is normal.
•  DTC P0967 is not set.

P0967

•  The ignition voltage is between 10.2-15.5 V.
•  The engine speed is greater than 400 RPM for 2 s.
•  The transmission is not in emergency mode.
•  Driving in D range.
•  TCM communication is normal.
•  DTC P0966 is not set.

Conditions for Setting the DTC

P0778

Deviation between commanded current and feedback current.

P0965

The TCM detects the error current more than 80 mA for 2.75 ms.

P0966

The TCM detects at least 5 times less than 23 mA current consumption of the SLC1 control circuit for 100 ms.

P0967

The TCM detects at least 5 times more than 1.333 A current consumption of the SLC1 control circuit for 100 ms.

Action Taken When the DTC Sets

P0778, P0965

•  DTC P0965 is a Type B DTC.
•  The TCM turns OFF all solenoids.
•  The TCM allows the vehicle after a stop to operate only in the second gear and "R" range.

P0966, P0967

•  DTCs P0966 and P0967 are Type B DTCs.
•  No self learning function.
•  The TCM turns OFF all solenoids.
•  The TCM allows the vehicle after a stop to operate only in the second gear and "R" range.

Conditions for Clearing the DTC

P0778, P0965

•  DTC P0967 is a Type B DTC.
•  The TCM detects the error current less than 50 mA for 2.75 ms.

P0966, P0967

•  DTCs P0966 and P0967 are Type B DTCs.
•  The current consumption of the SLC1 control circuit is 0.1-1.1 A for 500 ms.

Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the TCM is warmed up and the transmission is operated in 2nd gear long enough to ensure a 3°C (5°F) increase in TCM substrate temperature. This will place the TCM under the optimal conditions to test solenoid electrical DTCs.

Reference Information


Schematic Reference

Automatic Transmission Controls Schematics


Connector End View Reference

Component Connector End Views


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

1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
2. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in transmission fluid temperature, then operate the vehicle in Park for 5 s.
3. Observe the scan tool Clutch Pressure Control Solenoid Valve 1 Current parameter, the reading should be between 0.1-1.1 A.

Circuit/System Testing

Command the Clutch Pressure Control Solenoid Valve 1 with a scan tool. The value should change from 0.0-1.0 A.

If the value does not change, turn ignition OFF, remove the K71 Transmission Control Module. Connect a test lamp between the low reference circuit terminal 10 X2 at the K71 Transmission Control Module and the voltage supply component circuit terminal 11 X2 at the K71 Transmission Control Module. Command the Clutch Pressure Control Solenoid Valve 1 with a scan tool. The test lamp has to illuminate brighter with increasing current. If the test lamp always illuminate or always does not illuminate, replace the K71 Transmission Control Module.

Component Testing

Static Test

1. Ignition OFF, remove the K71 Transmission Control Module.
2. Test for 5-5.6 Ω at 20°C (68°F) between the low reference circuit terminal 10 X2 and the voltage supply circuit terminal 11 X2.
If less than the specified range, test the wiring harness for internal short. If the circuit test normal, replace the Q27A Pressure Control Solenoid Valve 1.
3. Test for infinite resistance between each terminal and the low reference circuit terminal 10 X2 and also to the voltage supply circuit terminal 11 X2.
If less than the specified range, replace the wiring harness.
4. If all circuit test normal, perform the Control Solenoid Valve Inspection .
If the inspection test normal, replace the control valve body.

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.
•  Wiring harness-Refer to Automatic Transmission Wiring Harness Replacement for replacement.

DTC P0731 > < DTC P0218