What Does P1749 Mean?
The Electronic Pressure Control (EPC) solenoid circuit voltage is below the expected range. This solenoid regulates line pressure in the transmission, and low circuit voltage affects shift quality and clutch engagement.
Common Causes
40%
Failed EPC solenoid with internal short or low resistance
30%
Corroded or damaged connector pins at solenoid or TCM
20%
Chafed or shorted wiring harness to ground
10%
Failed TCM/PCM internal short circuit
Diagnostic Steps
1
Step 1: Measure EPC solenoid resistance (typically 3-6 ohms) with connector disconnected
2
Step 2: Inspect transmission connector for corrosion, bent pins, or moisture intrusion
3
Step 3: Check wiring harness for damage, especially where it routes near exhaust or sharp edges
4
Step 4: Monitor EPC solenoid voltage and current draw using scan tool PID data during operation
5
Step 5: Test TCM output driver by backprobing circuit with oscilloscope during commanded pressure changes
Estimated Repair Cost
$150 - $700
Parts + labor, varies by vehicle and location
The Electronic Pressure Control (EPC) solenoid circuit voltage is below the expected range. This solenoid regulates line pressure in the transmission, and low circuit voltage affects shift quality and clutch engagement.
The most common cause of P1749 (Electronic Pressure Control Solenoid Circuit Low) is: Failed EPC solenoid with internal short or low resistance
Typical repair costs for P1749 range from $150 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Reduced transmission line pressure may cause slipping, delayed engagement, or erratic shifts. Vehicle remains drivable but transmission damage may occur if driven extensively.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1749 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission
Difficulty
Type
Manufacturer
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