Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET1997CHEVY EXPRESS G3500, VAN CARGO, 6.5 FREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 42 (ENGINE CONTROLS - TESTS W/CODES - 5.0L)TROUBLE CODE CHARTSCODE 68, OVERDRIVE RATIO ERROR - 4L80-E TRANSMISSIONNOTES
1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 F
Code 68, Overdrive Ratio Error - 4L80-E Transmission: Notes
1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 FSECTION Notes
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1995 GMC Vandura, 1995 GMC Rally, 1995 GMC Pickup, 1995 Chevrolet Sportvan, and 1995 Chevrolet Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Control module 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 indicated range signal to selected range. A faulty switch could set this code.
- Checks TCC for slippage while in a commanded lock-up state.
RENDER: 1.0x
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.