P0776

P0776-PRESSURE CONTROL SOLENOID B PERFORMANCE





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Linear Solenoid 2 is used to control input pressure to the Control Valve 2. The Control Valve 2 uses the input to modulate the line pressure to the appropriate supply pressure for the clutch. The TCM verifies the operation of the Control Valve 2 by monitoring the Pressure Switch 2. If a fault is detected, the transmission will go into limp in mode, the Torque Converter Clutch (TCC) will be disabled, the limp in gear will vary based on the current gear and other conditions, and the MIL will be illuminated.


Condition One:


When Monitored:
- Ignition on, engine running.

Set Condition:
- Pressure switch 2 is on for more than 310 ms after the transition of the Control Valve 2 from on to off 3 times.
- The electric fault of the Solenoid has not been detected after the above condition has been established within 10 seconds.

Condition Two:


When Monitored:
- Ignition on, engine running.
- TRS is in the D, 3, 2, or 1 position and Pressure Switch 8 is on.

Set Condition:
- Pressure switch 2 is off for more than 310 ms after the transition of the Control Valve 2 from off to on.
- The electric fault of the Solenoid has not been detected after the above condition has been established within 10 seconds.

Condition Three:


When Monitored:
- Ignition on, engine running.
- TRS is in the D, 3, 2, or 1 position and Pressure Switch 8 is on.

Set Condition:
- Pressure Switch 2 is off for more than 310 ms after a transition of the Control Valve 2 from on to off when the gear ratio is Neutral for more than 2 seconds.
- The electric fault of the Solenoid has not been detected after the above condition has been established within 10 seconds.

Condition Four:


When Monitored:
- Ignition on, engine running.
- Control Valve 2 continuous operation is off.

Set Condition:
- Pressure Switch 2 is on for more than 100 ms.
- The electric fault of the Solenoid has not been detected after the above condition has been established within 10 seconds.

Condition Five:


When Monitored:
- Ignition on, engine running.
- TRS is in the D, 3, 2, or 1 position and Pressure Switch 8 is on.
- Control Valve 2 continuous operation is on.

Set Condition:
- Pressure Switch 2 is off for more than 2 seconds.
- The electric fault of the Solenoid has not been detected after the above condition has been established within 10 seconds.







Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. AS68RC Pre-Diagnostic Troubleshooting Procedure



Diagnostic Test


1. CHECK IF DTC IS CURRENT

With the scan tool, view Transmission DTCs.

Is the status Active or is the Starts Since Set counter 2 or less for this DTC?

Yes

- Go To 2

No

- Go To 8



2. CHECK PRESSURE SWITCH 2 STATE

Ignition on, engine not running.

With the scan tool, view the Pressure Switch 2 state.

Does the scan tool display the Pressure Switch 2 as "On"?

Yes

- Go To 3

No

- Go To 5



3. CHECK PRESSURE SWITCH 2

Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid Assembly C2 harness connector


NOTE: Check connectors - Clean/repair as necessary.

Ignition on, engine not running.

With the scan tool, view the Pressure Switch 2 state.

Does the scan tool display the Pressure Switch 2 as "On"?

Yes

- Go To 4

No

- Inspect the internal wiring harness and connectors for shorts, corrosion, damage, or terminal push out. If no problems found, replace the Pressure Switch 2.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



4. CHECK THE (T801) PRESSURE SWITCH 2 SIGNAL CIRCUIT FOR A SHORT TO GROUND





Turn the ignition off to the lock position.

Disconnect the TCM C1 harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (T801) Pressure Switch 2 signal circuit to ground.

Is the resistance below 100k ohms?

Yes

- Repair the (T801) Pressure Switch 2 signal circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



5. CHECK PRESSURE SWITCH 2 SIGNAL CIRCUIT

Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid Assembly C2 harness connector


NOTE: Check connectors - Clean/repair as necessary.

Ignition on, engine not running.

With the scan tool, monitor the Pressure Switch 2 state in the following step.

Using a test light connected to ground, probe the (T801) Pressure Switch 2 signal circuit in the Transmission Solenoid Assembly C2 Harness connector.

Does the scan tool display the Pressure Switch 2 as "On" when the (T801) Pressure Switch 2 signal circuit is grounded with the test light?

Yes

- Go To 7

No

- Go To 6



6. CHECK THE (T801) PRESSURE SWITCH 2 SIGNAL CIRCUIT FOR AN OPEN





Turn the ignition off to the lock position.

Disconnect the TCM C1 harness connector.

Measure the resistance of the (T801) Pressure Switch 2 signal circuit between the Transmission Solenoid Assembly C2 harness connector and the TCM C1 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for shorts, corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM.

No

- Repair the (T801) Pressure Switch 2 signal circuit for an open.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



7. CHECK INTERNAL TRANSMISSION

Turn the ignition off to the lock position.

Remove the transmission oil pan.

Check the internal transmission harness, pins, terminals, and connectors for shorts, corrosion, damage, or terminal push out.

Visually inspect the valve body for debris, damage or leaking hydraulic paths.

Visually inspect for sticking or binding Control Valve(s).

Were there any problems found?

Yes

- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Replace the Pressure Switch 2.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test



8. CHECK WIRING AND CONNECTORS

The conditions necessary to set the DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle the wires while checking for shorted and open circuits.

Check for any Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. AS68RC Transmission Verification Test

No

- Test Complete.