Code 68, Overdrive Ratio Error: Notes
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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 test numbers on diagnostic chart.
- Code 68 will set under the following conditions: engine speed is 200 RPM greater than input speed, 4th gear is indicated, TCC is enabled, or if all conditions are met for 2 seconds.
- This test monitors signal sent to the PCM/TCM from transmission.
- This test confirms engine RPM signal to PCM/TCM.