Code 68, Overdrive Ratio Error: Notes

The PCM/TCM monitors the difference in engine RPM and input shaft RPM. With transmission in Drive, scan tester reading should show engine speed closely matching input speed.

NOTE: Test numbers refer to numbers on diagnostic chart.

Checks the indicated range signal to the selected range. A faulty switch could set this code.
Checks TCC for slippage while in a commanded lock-up state.