The OEM transmission is a GM 4L30-E. It is a computer-controlled overdrive transmission, using the 'optional' gear ratios:
- 2.86:1 1st gear
- 1.62:1 2nd gear
- 1.00:1 3rd gear
- 0.723:1 4th gear
- 2.00:1 reverse
Transfer case ratios - (:1) High: 1.00 Low: 2.48
Axle gear ratios - (:1) Front: 4.30 Rear: 4.30
Common Problems Edit
Often caused by a failing Mode Switch. This will also cause the PRNDL indicator to show the wrong gear, and may store a ???? code in the OBDII diagnostics, although the check-engine light does not light.
May also be caused by a clogged transmission filter.
May be caused by a lack of transmission fluid.