AutoCodes – Mercedes-Benz – P0733 Mercedes-Benz

P0733 Mercedes-Benz Code - Gear 3 Incorrect ratio

Quick Answer

This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by Transmission Control Module (TCM) as follows: Torque converter slip ratio = A x C/B A: Output shaft revolution signal from revolution sensor B: Engine speed signal from Engine Control Module (ECM) C: Gear ratio determined as gear position which TCM supposes If the actual gear position is higher than the position (3rd) supposed by TCM, the slip ratio will be more than normal. Common causes include Low transmission fluid level, Dirty transmission fluid, Shift solenoids. 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: P0733 Mercedes-Benz indicates Gear 3 Incorrect ratio.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Shift solenoids.
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.

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Code Popularity 11,664

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0733 Mercedes-Benz Description

This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by Transmission Control Module (TCM) as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from Engine Control Module (ECM)
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is higher than the position (3rd) supposed by TCM, the slip ratio will be more than normal. In case the ratio exceeds the specified value, TCM judges this diagnosis malfunction.

OBDII Code P0733 Mercedes-Benz - Gear 3 Incorrect ratio - AutoCodes.com — P0733 Mercedes-Benz Code - Gear 3 Incorrect ratio

What does this mean?

What are the Possible Causes of the DTC P0733 Mercedes-Benz?

Low transmission fluid level
Dirty transmission fluid
Shift solenoids
Transmission mechanical problems
Transmission hydraulic control circuit

How to Fix the DTC P0733 Mercedes-Benz?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0733 Mercedes-Benz code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0733 Mercedes-Benz code?

Need more information on how to fix the P0733 Mercedes-Benz code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0733 Mercedes-Benz Code

1. What does the OBDII code P0733 mean on a Mercedes-Benz?

Code P0733 indicates a "Gear 3 Incorrect Ratio," meaning the transmission is not achieving the expected gear ratio for third gear.

2. What are the common symptoms of code P0733 in a Mercedes-Benz?

Symptoms may include transmission slipping, trouble shifting gears, reduced acceleration, poor fuel economy, and the Check Engine Light illuminated.

3. What could cause the P0733 code on a Mercedes-Benz?

Causes include low transmission fluid, a faulty shift solenoid, worn clutch packs, damaged gears, or issues with the transmission control module.

4. Can driving with code P0733 damage my Mercedes-Benz?

Yes, prolonged driving with this code can lead to further transmission damage, reduced performance, and higher repair costs.

5. How do I diagnose code P0733 on a Mercedes-Benz?

Start by checking the transmission fluid level and condition. Use a diagnostic scanner to monitor transmission data, and inspect the shift solenoids, wiring, and internal transmission components.

6. How can low transmission fluid cause code P0733?

Low fluid can lead to poor hydraulic pressure, preventing proper gear engagement and causing an incorrect gear ratio.

7. Is replacing the transmission necessary for code P0733?

Not always. The issue might be resolved by repairing or replacing components like solenoids, clutch packs, or fixing electrical connections.

8. How much does it cost to fix code P0733 on a Mercedes-Benz?

Costs vary depending on the issue. Minor repairs like fluid replacement or solenoid replacement may cost a few hundred dollars, while major transmission repairs can exceed several thousand.

9. Can a faulty transmission control module trigger code P0733?

Yes, a malfunctioning transmission control module can fail to regulate gear shifts properly, leading to the incorrect ratio in third gear.

10. How can I prevent code P0733 from occurring on my Mercedes-Benz?

Perform regular transmission maintenance, including fluid checks and replacements, and address any transmission-related issues promptly to avoid further damage.