K 2500 Truck 4WD V6-262 4.3L VIN Z (1992)
Control Module: Description and Operation
Overdrive Ratio
Overdrive Ratio Error Circuit
The overdrive ratio is determined from input speed and engine speed.
When TCC is engaged in 4th gear, if there is more than a 200 rpm difference between engine speed and input speed for at least two seconds, code
68 will set.
While code 68 is set, the following fail-safe actions will be taken:
-
Inhibit 4th Gear
-
Inhibit TCC Operation
-
Use Default Value for Pressure (force motor duty cycle)
-
Assume Drive 4 Shift Pattern
The system will recover on the next ignition cycle.