What Does P1788 Mean?
The transmission control module has detected an open circuit in pressure control solenoid B. This means electrical continuity has been lost, preventing the solenoid from regulating hydraulic pressure for proper transmission operation.
Safety Warning
Can cause harsh shifting, transmission slipping, or failure to shift properly. May result in sudden loss of drive capability. Avoid extended driving until repaired.
Common Causes
45%
Failed pressure control solenoid B internal coil
25%
Damaged wiring or broken wire to solenoid B
15%
Corroded or damaged solenoid connector
10%
Transmission control module internal driver failure
5%
Broken solder joint in transmission wiring harness
Diagnostic Steps
1
Step 1: Check transmission fluid level and condition as low fluid can cause solenoid failure
2
Step 2: Test resistance of pressure control solenoid B with multimeter (typically 3-10 ohms)
3
Step 3: Inspect solenoid connector for corrosion, damage, or pushed-back terminals
4
Step 4: Check continuity from TCM connector to solenoid connector for wiring breaks
5
Step 5: Remove solenoid and inspect for physical damage or contamination if accessible
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
The transmission control module has detected an open circuit in pressure control solenoid B. This means electrical continuity has been lost, preventing the solenoid from regulating hydraulic pressure for proper transmission operation.
The most common cause of P1788 (Pressure Control Solenoid "B" Open Circuit) is: Failed pressure control solenoid B internal coil
Typical repair costs for P1788 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Can cause harsh shifting, transmission slipping, or failure to shift properly. May result in sudden loss of drive capability. Avoid extended driving until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1788 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission
Difficulty
Type
Manufacturer
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