OBD Guide

P0729

Gear 6 Incorrect Ratio

P0729 is an OBD-II diagnostic trouble code meaning: Gear 6 Incorrect Ratio. Common causes: low or contaminated transmission fluid, worn friction discs or gears. Estimated repair cost: $56–278.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Unstable operation in 6th gear
  • Automatic gear shifting
  • Check Engine light comes on
  • Decreased fuel efficiency
  • Acceleration problems

Causes

  • Low or contaminated transmission fluid
  • Worn friction discs or gears
  • Shift solenoids malfunction
  • Problems with shaft speed sensors
  • Mechanical damage in the gearbox

How to Fix

  1. Check the level and condition of the transmission fluid
  2. Diagnose the operation of switching solenoids
  3. Check input and output shaft speed sensors
  4. Perform diagnostics of the mechanical part of the gearbox
  5. If necessary, replace worn components

Related codes

Error P0729 by Vehicle Brand

FAQ

What does the P0729 code mean?

P0729 is an OBD-II diagnostic trouble code that indicates: Gear 6 Incorrect Ratio

What causes a P0729 error code?

The most common causes of P0729 include: Low or contaminated transmission fluid; Worn friction discs or gears; Shift solenoids malfunction; Problems with shaft speed sensors.

How do I fix a P0729 diagnostic trouble code?

To fix P0729: Check the level and condition of the transmission fluid. Diagnose the operation of switching solenoids. Check input and output shaft speed sensors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0729?

Yes, but get it checked soon

How much does it cost to fix P0729?

The estimated repair cost for P0729 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

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