P0748 GMC - Pressure Control Solenoid Circuit Electrical

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3
Table of contents

P0748 GMC Possible Causes

  • Low transmission fluid level
  • Dirty transmission fluid
  • Faulty Pressure Control Solenoid
  • Pressure Control Solenoid harness is open or shorted
  • Pressure Control Solenoid circuit poor electrical connection

How do I fix code P0748 GMC?

Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
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Tech Notes

When a transmission solenoid is malfunctioned, in most cases the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is dirty, it's recommended to change the transmission fluid and if possible removing the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a mechanical transmission failure and that the transmission will need to be rebuilt or replaced.

Cost of diagnosing the P0748 GMC code

Labor: 1.0

The cost of diagnosing the P0748 GMC code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the code detected?

When the Powertrain Control Module (PCM) detects a continuous open or short in the Pressure Control (PC) solenoid valve circuit the P0748 code is set.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Transmission shift shock

P0748 GMC Description

The Pressure Control (PC) solenoid valve is an electronic device that regulates transmission line pressure based on the current flow through its coil winding. The magnetic field produced by the coil moves the solenoid's internal valve which varies pressure to the pressure regulator valve. The Powertrain Control Module (PCM) controls the PC solenoid valve by applying a varying amount of amperage to the solenoid. The applied amperage can vary from 0.1 to 1.1 amps. Low amperage (0.1 amp) indicates high line pressure. High amperage (1.1 amps) indicates low line pressure. The duty cycle of the PC solenoid valve is expressed as a percentage of energized ON time. Zero percent indicates zero ON time (non-energized) or no current flow. Approximately 60% at idle indicates maximum ON time (energized) or high current flow. The PCM determines the appropriate line pressure for a given load by comparing the throttle position (TP) voltage, the engine speed and other inputs.
OBDII Code P0748 Gmc - Pressure Control Solenoid Circuit Electrical - AutoCodes.com

More Information

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Comments

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