Diagnostic Test

CHECK FOR CHARGING SYSTEM DTCS
1. With the scan tool, read Powertrain Control Module (PCM) DTCs.
  Are any Charging System DTCs set?
  
  Yes
  - Repair Charging System DTCs. Refer to STANDARD PROCEDURE .
  - Perform the TRANSMISSION VERIFICATION TEST to verify the Transmission and or TCM was not damaged. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 2
CHECK IF VEHICLE WAS JUMP STARTED WITH 24-VOLT SYSTEM
NOTE:
Some Recreational Vehicles (RVs), Buses, and Semi Tractors use 24V systems.
1. Check if the vehicle was jump started by a vehicle with a 24-volt charging system.
  Was the vehicle jump started by a vehicle with a 24-volt charging system?
  
  Yes
  - With the scan tool, erase TCM DTCs.
  - Perform the TRANSMISSION VERIFICATION TEST to verify the Transmission and or TCM was not damaged. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 3
CHECK INDICATED TCM BATTERY VOLTAGE
1. Start the Engine and raise the engine speed to 2, 000 rpm.
2. With the scan tool, read the TCM Battery Voltage for 60 seconds.
  Does the TCM Battery Voltage read greater than 16 volts at any time during the test?
  
  Yes
  - Go To 4
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK TCM VOLTAGE VS BATTERY VOLTAGE
1. Start the Engine and raise the engine speed to 2, 000 rpm.
2. With the scan tool, read the TCM Battery Voltage.
3. Measure the voltage at the Battery.
4. Compare the readings.
  Does the measured voltage reading match the scan tool TCM Battery Voltage reading?
  
  Yes
  - Repair the Charging System for an over charging condition in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 5
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 and record on the repair order.
  Did the DTC return?
  
  Yes
  - Replace the TCM in accordance with the Service information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL AND INSTALLATION .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  - Test complete.