Diagnostic Test

WARNING: This page is about a different car, the 2009 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

CHECK IF DTC IS CURRENT
1. With the scan tool, check the Starts Since Set counter for P0934.
  NOTE: This counter only applies to the last DTC set.
  
  Is the Starts Since Set counter 2 or less?
  
  Yes
  - Go to step 2
  No
  - Go to step 6
CHECK THE PCM AND WIRING
1. Turn the ignition off to the lock position.
2. Remove the Starter Solenoid Relay from the TIPM.
  CAUTION: Removal of the Starter Solenoid Relay from the TIPM will prevent the vehicle from being started in gear.
  
  WARNING: The Starter Solenoid Relay 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, under Transmission Sensors, 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 of the reading specified on the Transmission Simulator.
  
  Did the Line Pressure read within ± 14 kPa or 2.0 psi in all three positions?
  
  Yes
  - Replace the Line Pressure Sensor in accordance with the Service Information.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
CHECK THE (T38) LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Fig 1: CHECKING LINE PRESSURE SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND
Courtesy of CHRYSLER LLC
1. Turn the ignition off to the lock position.
2. Disconnect the PCM C4 harness connector and connect the PCM Pinout Box 8815.
3. Disconnect the Transmission Simulator 8333A and the Electronic Transmission Adapter kit.
  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 between ground and the (T38) Line Pressure Sensor Signal circuit.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the (T38) Line Pressure Sensor Signal circuit for a short to ground.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN

Fig 2: CHECKING 5-VOLT SUPPLY CIRCUIT FOR AN OPEN
Courtesy of CHRYSLER LLC
1. Disconnect the PCM C1 harness connector and connect the PCM Pinout Box 8815.
2. Measure the resistance of the (F856) 5-volt Supply circuit between Line Pressure Sensor/Variable Force Solenoid Assembly harness connector and the appropriate terminal of the PCM Pinout Box 8815.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 5
  No
  - Repair the (F856) 5-volt Supply circuit for an open.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND

Fig 3: CHECKING 5-VOLT SUPPLY CIRCUIT FOR SHORT TO GROUND
Courtesy of CHRYSLER LLC
1. Disconnect the PCM C1 harness connector and connect the PCM Pinout Box 8815.
2. Measure the resistance between ground and the (F856) 5-volt Supply circuit.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the (F856) 5-volt Supply circuit for a short to ground.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  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. If no problems are found, replace and program the PCM in accordance with the Service Information. With the scan tool, perform Quick Learn.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
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.
4. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.
  Where there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the 42RLE TRANSMISSION VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Test Complete.