What Does P1774 Mean?
The transmission hydraulic pressure sensor is reading lower than expected values. This could indicate low actual pressure or a faulty sensor providing incorrect readings.
Safety Warning
Low transmission pressure can cause slipping, delayed engagement, or complete loss of drive. Vehicle may become unsafe to drive and transmission damage can occur quickly.
Common Causes
35%
Low transmission fluid level causing actual low pressure
30%
Failed hydraulic pressure sensor reading incorrectly low
20%
Worn transmission pump not generating sufficient pressure
15%
Internal transmission leaks from worn seals or damaged clutch packs
Diagnostic Steps
1
Step 1: Check transmission fluid level immediately; top off if low and inspect for leaks
2
Step 2: Install mechanical pressure gauge and compare actual pressure to sensor reading
3
Step 3: If sensor reads low but actual pressure is normal, replace pressure sensor
4
Step 4: If actual pressure is low, perform line pressure test at various RPMs
5
Step 5: Diagnose internal transmission issues (pump, seals, clutches) if pressure remains low
Estimated Repair Cost
$150 - $2,500
Parts + labor, varies by vehicle and location
The transmission hydraulic pressure sensor is reading lower than expected values. This could indicate low actual pressure or a faulty sensor providing incorrect readings.
The most common cause of P1774 (Hydraulic Pressure Sensor 1 Too Low) is: Low transmission fluid level causing actual low pressure
Typical repair costs for P1774 range from $150 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Low transmission pressure can cause slipping, delayed engagement, or complete loss of drive. Vehicle may become unsafe to drive and transmission damage can occur quickly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1774 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission Hydraulic System
Difficulty
Type
Manufacturer
Recommended Tools
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