P0746

P0746-LINE PRESSURE SOLENOID PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Line Pressure Solenoid regulates the Line Pressure (Oil Pump discharge pressure) which is controlled by the Transmission Control Module (TCM). If the line pressure does not reach at the desired pressure due to driving conditions, the possibility of belt slippage can occur. The gear ratio changes to a value beyond the maximum gear ratio which is a calculation between the Primary Pulley speed and the Secondary Pulley speed. If the gear ratio exceeds a predetermined limit a DTC will set.

- When Monitored:
Ignition on, engine running with the transmission in a valid forward gear.

Vehicle speed greater than 10 Km/h (6 mph).

Accelerator Pedal Position (APP) greater than 12.5%.

Engine rpm greater than 450 rpm.

Primary Pulley Speed grater than 500 rpm.

No active DTCs from the following:

- Line Pressure Solenoid
- Temperature Sensor
- Primary or Secondary Pressure Sensor
- Transmission Range Sensor
- Step Motor
- Secondary Solenoid electrical
- Input and Output Speed Sensor
- Torque Convertor Clutch
- CAN Bus
- Over Temperature Condition
- Set Condition:
Condition one: Gear ratio is greater than 2.7 - 2 for the period of 0.2 of a second (first trip).

Condition two: Gear ratio is greater than 3.5 - 1 for the period of 0.1 of a second (second trip).





Always perform the CVT Pre-Diagnostic Troubleshooting procedure before proceeding. Testing and Inspection.

1. CHECK TO SEE IF THE DTC IS ACTIVE
1. With the scan tool, read 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 5

2. CHECK IF SPEED SENSOR DTCS ARE PRESENT
1. With the scan tool, read Transmission DTCs.

Are there any Active or Stored Speed Sensor DTCs also present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 3

3. CHECK THE (T20) LINE PRESSURE SOLENOID CONTROL CIRCUIT




1. Turn the ignition off to the lock position.
2. Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
3. Ignition on, engine not running.
4. With the scan tool, actuate the Line Pressure Solenoid (PL).
5. Using a 12-volt test light connected to ground, check the (T20) Line Pressure Solenoid Control circuit in the Transmission Solenoid/Pressure Switch Assembly harness connector.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Replace the Valve Body.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

No

- Go To 4

4. CHECK THE TRANSMISSION CONTROL MODULE




1. Turn the ignition off to the lock position.
2. Disconnect the TCM C1 harness connector.
3. Connect a jumper wire between the (T20) Line Pressure Solenoid Control circuit in the TCM C1 harness connector and B(+).
4. Using a 12-volt test light connected to ground, check the (T20) Line Pressure Solenoid Control circuit in the Transmission Solenoid/Pressure Switch Assembly harness connector.

Does the test light illuminate brightly?

Yes

- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

No

- Repair the (T20) Line Pressure Solenoid Control circuit for an open (high resistance).
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

5. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the CVT TRANSMISSION VERIFICATION TEST. CVT Transmission Verification Test.

No

- Test Complete.