DTC 44 - EGR Pulse Width Error: Notes

1987 Chevrolet Hi-Cube 6.2 J, 400/M40SECTION Notes
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 GMC Yukon, 1994 GMC Suburban, 1994 GMC Pickup, 1994 GMC Cab & Chassis, and 1994 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

PCM operates the normally-open solenoid to control the EGR valve. By providing a ground path the PCM energizes the solenoid allowing vacuum to pass to the EGR. During normal operation, the PCM compares EGR duty cycle signal with EGR control pressure/BARO signal and makes adjustments in duty cycle accordingly. If there is a difference in the PCM command and what is at the EGR valve sensed by the EGR control pressure/BARO sensor, PCM makes minor adjustments to correct. DTC 44 will set when no ignition voltage is present on the EGR control circuit when EGR solenoid is commanded on. PCM will default to shut down the EGR.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. This step determines if DTC 44 is the result of a hard failure or an intermittent condition.
  2. This step checks if PCM and wiring are okay.
  3. This step checks the EGR solenoid.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.