What Does P1793 Mean?
DTC P1793 indicates that the transmission pressure control solenoid "B" has an open circuit condition. The PCM/TCM has detected a break in the electrical circuit feeding the solenoid, meaning it cannot regulate hydraulic line pressure in the designated clutch pack or band. This results in harsh or erratic shifts and potential transmission damage if driven extensively.
Safety Warning
Loss of proper pressure control can cause harsh shifts, transmission slipping, or limp mode, reducing vehicle control and potentially leaving the driver stranded.
Common Causes
30%
Broken or corroded wiring in the solenoid circuit
30%
Failed pressure control solenoid "B" (internal open coil)
20%
Damaged connector or terminal at the transmission case connector
10%
Faulty TCM/PCM solenoid driver circuit
10%
Internal transmission harness damage
Diagnostic Steps
1
Read freeze frame data and note the operating conditions when the fault was set.
2
Measure resistance across the pressure control solenoid "B" terminals at the transmission case connector; compare to manufacturer specification (typically 3–7 ohms).
3
Perform a continuity test on the wiring harness between the TCM connector and the transmission case connector for the solenoid "B" circuit.
4
Inspect the transmission case connector and internal harness for damaged, spread, or corroded pins.
5
Command the solenoid on via a bi-directional scan tool and verify current draw is within specification.
6
If the wiring and solenoid test good, suspect the TCM solenoid driver and test supply voltage and ground at the TCM connector.
Estimated Repair Cost
$200 - $1,200
Parts + labor, varies by vehicle and location
DTC P1793 indicates that the transmission pressure control solenoid "B" has an open circuit condition. The PCM/TCM has detected a break in the electrical circuit feeding the solenoid, meaning it cannot regulate hydraulic line pressure in the designated clutch pack or band. This results in harsh or e...
The most common cause of P1793 (Pressure Control Solenoid "B" Open Circuit) is: Broken or corroded wiring in the solenoid circuit
Typical repair costs for P1793 range from $200 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Loss of proper pressure control can cause harsh shifts, transmission slipping, or limp mode, reducing vehicle control and potentially leaving the driver stranded.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1793 to identify the root cause.
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Powertrain
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Transmission
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