Diagnostic guide for P0868

Diagnostic Guide for P0868 - Secondary Pressure Down

OBDII code P0868 indicates a problem with the secondary pressure control in the transmission system. The goal of this diagnostic guide is to identify the underlying issue causing the engine light to illuminate and ensure proper transmission function.

✓

Difficulty

Intermediate

⏱

Estimated Time

30-60 Minutes

Estimated Diagnostic Cost

$0-$100

Typical shop charge to perform this diagnostic process. Repair parts and labor are not included.

⚙

Tools Needed

OBDII scanner, multimeter, basic hand tools, vehicle service manual

Safety Notes

Ensure the vehicle is on a flat surface and securely lifted if necessary. Be cautious of hot engine components and moving parts during the inspection.

Step 1

Scan for Codes

Instruction Connect the OBDII scanner to the vehicle's diagnostic port and retrieve any stored trouble codes.

Expected result The scanner displays OBDII code P0868 along with any other related codes.

If Pass If P0868 is confirmed, proceed to the next step to inspect the wiring and connectors.

If Fail If no codes are found, check the scanner's connection and ensure the vehicle's ignition is in the 'ON' position.

Ask Coddy about this step

Coddy can help with this step only. Tell me what you tested or what result you got.

Step 2

Inspect Wiring and Connectors

Instruction Visually inspect the wiring and connectors related to the Pressure Control Solenoid Valve 'B' for any signs of damage, corrosion, or loose connections.

Expected result Wiring and connectors appear intact without visible damage.

If Pass If the wiring is in good condition, proceed to test the solenoid operation.

If Fail If damage is found, repair or replace the affected wiring or connectors.

Ask Coddy about this step

Coddy can help with this step only. Tell me what you tested or what result you got.

Step 3

Test the Pressure Control Solenoid Valve 'B'

Instruction Using a multimeter, test the resistance of the Pressure Control Solenoid Valve 'B' according to the specifications in the vehicle service manual.

Expected result Resistance readings fall within the specified range.

If Pass If the solenoid tests within specifications, check the Transmission Pressure Sensor 'A'.

If Fail If the resistance is out of range, the solenoid may be faulty and should be replaced.

Ask Coddy about this step

Coddy can help with this step only. Tell me what you tested or what result you got.

Step 4

Check Transmission Pressure Sensor 'A'

Instruction Test the Transmission Pressure Sensor 'A' for proper voltage output while the vehicle is running, using the multimeter.

Expected result Voltage output is within the manufacturer's specified range.

If Pass If the sensor is functioning correctly, proceed to check the Transmission Control Module (TCM).

If Fail If the voltage is incorrect, the sensor may need to be replaced.

Ask Coddy about this step

Coddy can help with this step only. Tell me what you tested or what result you got.

Step 5

Inspect TCM and Reprogram if Necessary

Instruction Check for any updates or service bulletins related to the TCM for the specific vehicle model. If applicable, reprogram the TCM as per manufacturer guidelines.

Expected result TCM is updated or reprogrammed successfully.

If Pass If the TCM is functioning correctly, clear the codes and test drive the vehicle to confirm the issue is resolved.

If Fail If reprogramming fails, further diagnosis of the TCM may be necessary.

Ask Coddy about this step

Coddy can help with this step only. Tell me what you tested or what result you got.