Engine-Codes.com
Engine-Codes – Subaru – P0734 Subaru

P0734 Subaru Code - Gear 4 Incorrect Ratio

Quick Answer

The P0734 code for Subaru vehicles indicates that there is an incorrect gear ratio detected in the transmission's fourth gear. Common causes include Low transmission fluid level or dirty transmission fluid, Malfunctioning shift solenoids, Faulty transmission control module. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0734 Subaru indicates Gear 4 Incorrect Ratio.
Common causes
Common causes include Low transmission fluid level or dirty transmission fluid, Malfunctioning shift solenoids, Faulty transmission control module.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Sep 06, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0734 Subaru Description

The P0734 code for Subaru vehicles indicates that there is an incorrect gear ratio detected in the transmission's fourth gear. This means that the transmission is not shifting properly into fourth gear, which can lead to issues with acceleration, fuel efficiency, and overall performance. When the transmission is unable to engage the correct gear ratio, it can cause the engine to work harder than necessary, leading to increased wear and tear on the engine and transmission components.

OBDII Code P0734 Subaru - Gear 4 Incorrect Ratio
P0734 Subaru Code - Gear 4 Incorrect Ratio

Common Causes of P0734 Subaru

  1. Low transmission fluid level or dirty transmission fluid
  2. Malfunctioning shift solenoids
  3. Faulty transmission control module
  4. Worn or damaged transmission components
  5. Electrical issues such as wiring harness damage

Symptoms of P0734 Subaru

  1. Slipping or delayed engagement when shifting into fourth gear
  2. Harsh or erratic shifting
  3. Decreased fuel efficiency
  4. Engine revving higher than usual at cruising speeds
  5. Illumination of the Check Engine Light

How to Fix P0734 Subaru

  1. Check and top off transmission fluid levels or perform a transmission fluid flush and filter replacement
  2. Inspect and replace any faulty shift solenoids
  3. Test and potentially replace the transmission control module
  4. Inspect and repair or replace any worn or damaged transmission components
  5. Check and repair any damaged wiring harnesses or electrical connections

Cost to Fix P0734 Subaru

The cost of repairing a P0734 code on a Subaru can vary depending on the specific cause of the issue and the extent of the repairs needed. In general, the cost can range from $200 to $800 or more. This cost typically includes parts such as solenoids or transmission components, as well as labor costs. It's important to note that diagnostic time and labor rates can vary, so it's recommended to get a specific estimate from a trusted auto repair shop.

What does this mean?

Tech Notes for P0734 Subaru

Start by inspecting the transmission fluid level and condition, and change fluid if necessary.

When is the Code Detected?

P0734 is detected when A/T cannot be shifted to the 4th gear position even if electrical circuit is good.

Need more information about the P0734 Subaru code?

Need more information on how to fix the P0734 Subaru code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0734 Subaru code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0734 Subaru Code

1. What does OBDII code P0734 on a Subaru mean?

Code P0734 indicates that there is an incorrect gear ratio in the transmission's fourth gear.

2. What are the common symptoms of OBDII code P0734 in a Subaru?

Common symptoms include difficulty shifting into or out of fourth gear, slipping when in fourth gear, delayed engagement, and the transmission may go into limp mode.

3. What are the possible causes of OBDII code P0734 in a Subaru?

Potential causes include low transmission fluid levels, dirty or contaminated transmission fluid, faulty shift solenoids, a worn clutch or clutch pack, damaged transmission components, or issues with the transmission control module.

4. How can I diagnose OBDII code P0734 in my Subaru?

Diagnosis typically involves checking the transmission fluid level and condition, conducting a visual inspection for any visible damage, performing a scan tool test to check for other trouble codes, and potentially conducting a road test to observe the transmission's behavior.

5. How can I repair OBDII code P0734 in my Subaru?

Possible repair options include topping up or changing the transmission fluid, replacing faulty shift solenoids, repairing or replacing damaged transmission components, addressing any clutch-related issues, and resetting the transmission control module.

6. Can driving with OBDII code P0734 in a Subaru cause further damage?

Continuing to drive with code P0734 present can potentially lead to further damage to the transmission components, so it is advisable to address the issue promptly.

7. Will resetting the check engine light make OBDII code P0734 go away?

Resetting the check engine light may temporarily clear the code, but if the underlying issue causing P0734 is not addressed, the code is likely to return.

8. Is it safe to continue driving my Subaru with OBDII code P0734?

Driving with code P0734 can be risky as it may result in transmission issues such as slipping or failure to engage gears properly. It's best to have the problem diagnosed and repaired as soon as possible.

9. How much does it typically cost to repair OBDII code P0734 in a Subaru?

The cost of repairing P0734 can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, especially if significant transmission components need to be replaced.

10. Can I fix OBDII code P0734 in my Subaru myself, or should I take it to a professional mechanic?

While some simple maintenance tasks like checking and topping up transmission fluid can be done by DIY enthusiasts, diagnosing and repairing complex transmission issues associated with P0734 is usually best left to professional mechanics with the necessary expertise and tools.

Discuss the causes and fixes for P0734 Subaru OBDII Code

Submit a New Comment

Code P0734 Subaru comments

No comments found for this page.