41TE NGC

P0935-LINE PRESSURE SENSOR CIRCUIT HIGH







Theory of Operation

Line pressure is electronically controlled by the Transmission Control System and is measured by the Line Pressure Sensor (LPS). The desired line pressure is continuously being compared to the actual line pressure and is regulated by electronically changing the duty cycle of the Pressure Control Solenoid (PCS). (5% duty cycle = solenoid off = max line pressure, 62% duty cycle = solenoid on = min line pressure).

The Transmission Control System calculates the desired line pressure based on inputs from the transmission and engine. A calculated torque input to the transmission is used as the primary input of the desired line pressure calculation and is called Torque Based Line Pressure. In addition, the line pressure is set to a preset level during shifts and in Park and Neutral to ensure consistent shift quality.

The monitored Line Pressure Sensor voltage should always be between 0.35 and 4.75 volts. Any monitored voltages outside these parameters indicate a Line Pressure Sensor or wiring problem and will cause either DTC P0934 or P0935 to set.

- When Monitored:
Continuously with ignition on and engine running.

- Set Condition:
This DTC will set if the monitored Line Pressure Sensor voltage is greater than or equal to 4.75 volts for the period of 0.18 of a second.





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

1. CHECK TO SEE IF DTC IS CURRENT
1. With the scan tool, Check the Starts Since Set counter for P0935.

NOTE: This counter only applies to the last DTC set.

Is the Starts Since Set counter 2 or less?

Yes

- Go To 2

No

- Go To 6

2. CHECK THE PCM AND WIRING
1. Turn the ignition off to the lock position.
2. Remove the Ignition Switch Feed fuse from the TIPM.

CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear.

WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in possible serious or fatal injury.

3. Install the Transmission Simulator 8333A and the Electronic Transmission Adapter kit.
4. Ignition on, engine not running.
5. With the scan tool, monitor the Line Pressure.
6. Using the Transmission Simulator, set the rotary switch to each of the three line pressure positions.

NOTE: All three scan tool Line Pressure readings should be steady and ± 14 kPa or 2.0 psi (0.2 of a volt) of the reading specified on the Transmission Simulator.

Did the Line Pressure read within ± 14 kPa or 2.0 psi (0.2 of a volt) in all three positions?

Yes

- Replace the Line Pressure Sensor.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

No

- Go To 3

3. CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN




1. Turn the ignition off to the lock position.
2. Disconnect the Transmission Simulator 8333A and the Electronic Transmission Adapter kit.
3. Disconnect the PCM C2 harness connector and connect the PCM Pinout Box 8815.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.

4. Measure the resistance of the (K900) Sensor Ground circuit between the Line Pressure Sensor/Variable Force Solenoid Assembly harness connector and the appropriate terminal of the PCM Pinout Box 8815.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (K900) Sensor Ground circuit for an open.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

No

- Go To 4

4. CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN




1. Disconnect the PCM C4 harness connector and connect the PCM Pinout Box 8815.
2. Measure the resistance of the (T38) Line Pressure Sensor Signal circuit between the Line Pressure Sensor/Variable Force Solenoid Assembly harness connector and the appropriate terminal of the PCM Pinout Box 8815.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (T38) Line Pressure Sensor Signal circuit for an open.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

No

- Go To 5

5. CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE




1. Ignition on, engine not running.
2. With the scan tool under TIPM, actuate the Transmission.
3. Measure the voltage of the (T38) Line Pressure Sensor Signal circuit.

Is the voltage above 5.5 volts?

Yes

- Repair the (T38) Line Pressure Sensor Signal circuit for a short to voltage.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

No

- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins that may apply. If no problems are found, replace and program the PCM. With the scan tool perform the Quick Learn procedure Quick Learn Procedure.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

6. CHECK 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.
4. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.
5. Perform any service bulletins that may apply.

Where there any problems found?

Yes

- Repair as necessary.
- Perform the 40/41TE TRANSMISSION VERIFICATION TEST. 40/41TE Transmission Verification Test.

No

- Test Complete.