Diagnostic Test

CHECK FOR AN ACTIVE CONDITION
1. With the scan tool, read Transmission Control Module (TCM) DTCs and record on the repair order.
2. Record the Event Data and Environmental Data.
3. With the scan tool, erase DTCs.
4. Raise the vehicle on the hoist.
5. Start the Engine.
6. Select 4th gear to keep the Transmission from shifting into 5th gear or higher gear.
7. With the scan tool, read the Input Speed Sensor rpm.
8. Firmly apply the Brake Pedal and place the Shifter in DRIVE.
  WARNING:
  To avoid personal injury or death, keep hands and feet clear of rotating wheels.
9. Release the Brakes and raise the engine speed to allow the Transmission to perform a 2-3 and 3-4 upshift while observing the Input Speed Sensor rpm.
  Did the Input Speed Sensor display an rpm above 7, 700 at any time during the test?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR TRANSMISSION INTERNAL FAILURE
1. Remove the Transmission Oil Pan and Filter and inspect for excessive debris such as clutch friction material or metal contamination. Refer to FLUID AND FILTER, REMOVAL AND INSTALLATION .
  Is there any indication of an internal Transmission failure?
  
  Yes
  - Repair the Transmission in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 3
CHECK SPEED SENSORS AND WIRING
NOTE:
The speed sensors are part of the internal wiring harness.
1. Check the Output and Input Speed Sensors wiring for high resistance and high resistance short to ground. Also check connections for corrosion and pushed out terminals.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 4
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
  - 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.