Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read all DTCs and record on the repair order.
2. Record the Event Data and Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. Read TCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE LINE PRESSURE CONTROL SOLENOID
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Measure the resistance of the Line Pressure Control Solenoid circuit between the (T78) Solenoid Supply 1 circuit and the (T812) Pressure Control Solenoid Line Pressure circuit at the TCM harness connector.
  Is the resistance of the Line Pressure Control Solenoid circuit between 5.5 and 6.5 Ohms?
  
  Yes
  - Go To 3
  No
  - Before replacing the solenoid below verify no high resistance in the harness between the TCM and the Transmission Bulkhead connector.
  - Replace the Line Pressure Control Solenoid in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
CHECK THE (T78) SOLENOID SUPPLY 1 CIRCUIT FOR AN OPEN
1. Disconnect the TCM harness connector.
2. Measure the resistance of the (T78) Solenoid Supply 1 circuit between the Transmission Assembly harness connector and the TCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (T78) Solenoid Supply 1 circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
CHECK THE (T78) SOLENOID SUPPLY 1 CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (T78) Solenoid Supply 1 circuit.
  Is there continuity between ground and the (T78) Solenoid Supply 1 circuit?
  
  Yes
  - Repair the (T78) Solenoid Supply 1 circuit for a short to ground.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Go To 5
CHECK THE (T78) SOLENOID SUPPLY 1 CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Measure the resistance between the (T78) Solenoid Supply 1 circuit and all other circuits in the TCM harness connector.
  Is there continuity between the (T78) Solenoid Supply 1 circuit and any other circuits in the TCM harness connector?
  
  Yes
  - Repair the (T78) Solenoid Supply 1 circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Go To 6
CHECK THE (T812) PRESSURE CONTROL SOLENOID LINE PRESSURE CIRCUIT FOR AN OPEN
1. Measure the resistance of the (T812) Pressure Control Solenoid Line Pressure circuit between the Transmission Assembly harness connector and the TCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (T812) Pressure Control Solenoid Line Pressure circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
CHECK THE (T812) PRESSURE CONTROL SOLENOID LINE PRESSURE CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (T812) Pressure Control Solenoid Line Pressure circuit.
  Is there continuity between ground and the (T812) Pressure Control Solenoid Line Pressure circuit?
  
  Yes
  - Repair the (T812) Pressure Control Solenoid Line Pressure circuit for a short to ground.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Go To 8.
CHECK THE (T812) PRESSURE CONTROL SOLENOID LINE PRESSURE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Measure the resistance between the (T812) Pressure Control Solenoid Line Pressure circuit and all other circuits in the TCM harness connector.
  Is there continuity between the (T812) Pressure Control Solenoid Line Pressure circuit and any other circuits in the TCM harness connector?
  
  Yes
  - Repair the (T812) Pressure Control Solenoid Line Pressure circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Go To 9
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all TCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all TCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read TCM DTCs.
  Did the DTC return?
  
  Yes
  - If this Electronic Control Unit (ECU) is being replaced with a new unit, a diagnostic scan tool MUST be used to align the PROXI configuration data into the new ECU. Follow the routine outlined in the diagnostic scan tool for PROXI Configuration Alignment under Body Control Module (BCM) Miscellaneous Functions menu.
  - Replace the Transmission Control Module (TCM) and perform the PROXI Configuration Alignment procedures in accordance with the Service information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  - Test Complete.