OBD Guide

P0734

Gear 4 Incorrect Ratio

P0734 is an OBD-II diagnostic trouble code meaning: Gear 4 Incorrect Ratio. Common causes: wear of friction discs 4th gear, low transmission fluid level. Estimated repair cost: $56–278.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Erratic gear shifting
  • Delays when switching to 4th gear
  • Power dips
  • Transmission fluid overheating
  • Check Engine light comes on

Causes

  • Wear of friction discs 4th gear
  • Low transmission fluid level
  • ATF contamination or degradation
  • Shift solenoids malfunction
  • Problems with speed sensors

How to Fix

  1. Check the level and condition of the transmission fluid
  2. Scan TCM Trouble Codes
  3. Check operation of shift solenoids
  4. Diagnose the mechanical condition of the transmission
  5. If necessary, replace worn components

Related codes

Error P0734 by Vehicle Brand

FAQ

What does the P0734 code mean?

P0734 is an OBD-II diagnostic trouble code that indicates: Gear 4 Incorrect Ratio

What causes a P0734 error code?

The most common causes of P0734 include: Wear of friction discs 4th gear; Low transmission fluid level; ATF contamination or degradation; Shift solenoids malfunction.

How do I fix a P0734 diagnostic trouble code?

To fix P0734: Check the level and condition of the transmission fluid. Scan TCM Trouble Codes. Check operation of shift solenoids. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0734?

Limited driving only, diagnose soon

How much does it cost to fix P0734?

The estimated repair cost for P0734 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

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