P0735 - Gear 5 Incorrect Ratio
The transmission control module (TCM) has detected that the gear ratio for 5th gear is outside the expected range. This indicates internal transmission slippage or a mechanical failure, often due to worn clutches, valve body issues, or low fluid pressure. The TCM monitors input and output shaft speeds to calculate ratios; a mismatch triggers this code.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or delayed shifting into 5th gear
- Transmission slipping or shuddering at highway speeds
- Reduced fuel economy
2. Most Common Causes
- Low or contaminated transmission fluid
- Worn or damaged clutch packs in 5th gear
- Faulty shift solenoid or valve body
- Internal transmission mechanical failure
3. Step-by-Step Diagnosis
Step 1: Check transmission fluid level and condition; top off or replace if necessary.
Step 2: Scan for additional codes and perform a transmission pressure test.
Step 3: Inspect wiring and connectors to the transmission control module and solenoids.
Step 4: If no external issues found, internal inspection of clutch packs and valve body is required.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Driving with P0735 can cause further transmission damage. It is not recommended to drive long distances; have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Repairs can range from a simple fluid change ($100-$250) to a full transmission rebuild ($1,500-$4,000).
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.