What Does P1735 Mean?
The transmission control module has detected a problem with the first gear position switch circuit. This switch confirms the transmission is in first gear. Circuit faults prevent accurate gear position monitoring.
Common Causes
40%
Faulty first gear pressure switch or position sensor
25%
Damaged wiring or connector between switch and TCM
20%
Low transmission fluid affecting hydraulic pressure to switch
10%
Internal transmission mechanical issue preventing first gear engagement
5%
Transmission control module malfunction
Diagnostic Steps
1
Step 1: Check transmission fluid level and condition; verify proper fill level
2
Step 2: Inspect transmission connector and wiring to first gear switch for damage or corrosion
3
Step 3: Test first gear pressure switch resistance and voltage signal with multimeter
4
Step 4: Monitor switch operation in real-time with scan tool while shifting through gears
5
Step 5: Replace first gear pressure switch if testing indicates failure
Estimated Repair Cost
$150 - $500
Parts + labor, varies by vehicle and location
The transmission control module has detected a problem with the first gear position switch circuit. This switch confirms the transmission is in first gear. Circuit faults prevent accurate gear position monitoring.
The most common cause of P1735 (First Gear Switch Circuit Malfunction) is: Faulty first gear pressure switch or position sensor
Typical repair costs for P1735 range from $150 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transmission may not shift properly or may enter limp mode limiting speed. Can cause unexpected shift behavior affecting vehicle control.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1735 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Manufacturer
Recommended Tools
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