P0734 Mercedes-Benz Code - Gear 4 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 (4th) 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
- P0734 Mercedes-Benz indicates Gear 4 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.
Code P0734 Mercedes-Benz Description
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 (4th) supposed by TCM, the slip ratio will be more than normal. In case the ratio exceeds the specified value, TCM judges this diagnosis malfunction.
What are the Possible Causes of the DTC P0734 Mercedes-Benz?
- Low transmission fluid level
- Dirty transmission fluid
- Shift solenoids
- Transmission mechanical problems
- Transmission hydraulic control circuit
How to Fix the DTC P0734 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0734 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.
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Frequently Asked Questions about P0734 Mercedes-Benz Code
1. What does the OBDII code P0734 mean on a Mercedes-Benz?
P0734 indicates that the transmission control module has detected an incorrect gear ratio for 4th gear, which could result from mechanical or electronic issues.
2. What are the common symptoms of code P0734 in a Mercedes-Benz?
Symptoms may include hesitation or slipping in 4th gear, poor acceleration, transmission shifting issues, or the check engine light turning on.
3. What causes the P0734 code in a Mercedes-Benz?
Common causes include low or dirty transmission fluid, a malfunctioning solenoid, worn-out clutch packs, damaged gears, or a faulty transmission control module.
4. Can driving with a P0734 code cause further damage?
Yes, continuing to drive with this code can worsen transmission damage, increase repair costs, or lead to unsafe driving conditions.
5. How do I diagnose the P0734 code in my Mercedes-Benz?
Start by checking the transmission fluid level and quality, inspecting the wiring and connectors, and using a diagnostic scanner to monitor transmission data.
6. Can low transmission fluid cause the P0734 code?
Yes, low or degraded transmission fluid can impair hydraulic pressure, leading to gear ratio errors like P0734.
7. How much does it cost to fix a P0734 code on a Mercedes-Benz?
Repair costs vary depending on the issue, ranging from $100 for a fluid change to over $2,000 for major transmission repairs.
8. Can resetting the check engine light fix the P0734 code?
Resetting the light without addressing the root cause will not fix the issue, and the code is likely to return.
9. Is a transmission rebuild necessary for the P0734 code?
Not always. Minor issues like low fluid or a faulty solenoid might resolve the problem, but severe damage could require a rebuild or replacement.
10. What should I do if my Mercedes-Benz shows the P0734 code?
Have the vehicle inspected by a qualified mechanic as soon as possible to prevent further damage and ensure safe operation.
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