What causes a P0735 code?

P0735 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P0735 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0735 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P0735

Incorrect Gear 5 Ratio - Transmission Slippage Detected

What it means

The Transmission Control Module (TCM) detected that the output shaft speed was incorrect compared to the input shaft speed while in 5th gear. This indicates internal mechanical slippage, fluid pressure issues, or a malfunctioning solenoid.