Transmission Control Systems: Testing and Inspection
PRE-DIAGNOSTIC CHECK OUT1.
Note: Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level per the Service Information.
Note: Always perform diagnostics with a fully charged battery to avoid false symptoms.
With the scan tool, read Engine DTC's. Check and repair all Engine DTC's prior to performing any transmission symptom diagnostics.
With the scan tool, read Transmission DTC's. Record all DTC's and 1 Trip Failures.
Note: Diagnose 1 Trip Failures as a fully matured DTC.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test for P0706 Check Shifter Signal. P0706
For Gear Ratio DTC's, check and record all CVI's.
Most DTC's set on start up but some must be set by driving the vehicle such that all diagnostic monitors have run.
Note: Verify flash level of Powertrain Control Module. Some problems are corrected by software upgrades to the Transmission and Engine software.
Note: Check for applicable TSB's related to the problem.
Were any repairs made that fixed the customer's complaint?
Yes >> Testing complete.
No >> Refer to the diagnostic test procedure related to the DTC.