Branch A - Not Working/Won't Engage

CAN BUSS ERROR

Info: The EZ TRAC ECU is not communicating with the display.

Possible Causes & Actions:

Loose connector at display or ECU → Inspect/reseat; check pins/corrosion
Wire unplugged or damaged in harness → Inspect ECU↔display harness; repair/replace section
No power to ECU → Check fuse/relay; verify ECU power pin voltage (IGN ON)

Error Code Detected

The display is showing an error code. Please refer to Branch C for specific error code troubleshooting.

→ Go to Branch C (Error Codes)

Have you had the dash apart recently?

Check Display Connection

Action: Check connector on back of display, reseat and verify latch/pin fit

Proceeding to Fuse Check

Moving to fuse and power system diagnostics.

Are the fuses all good in EZ TRAC fuse/relay box?

Ref: View Fuse & Relay Box Picture

Replace Fuse

Action: Replace fuse and check display

Is there 12V power at the 20A fuse?

Ref: View Fuse & Relay Box Picture

Trace KEY HOT Wire

Action: Trace KEY HOT wire (KEY HOT wire in dash OR wire 3 in connector A1 cab leg)

Ref: Download Electrical Schematic – Connector A1

If you unplug Relay 1 (main next to 20A fuse) and plug it back in, does it click?

Ref: View Fuse & Relay Box Picture

Check KEY HOT

Action: Check KEY HOT (same as Q4 action)

Is GND (black wires in cab bus connector B3) < 0.3Ω to chassis?

Ref: Download Electrical Schematic – Connector B3

Repair Ground Path

Action: Investigate ground path; repair as needed, then retest

Display or Wiring Issue

Action: You have a defective display or wires to display connector are damaged

Initial Setup Check

Info: Ensure valid state: In gear, park brake released, brake pedal not depressed, button pressed

Does button flash when you press it (truck running in gear)?

Is there oil in the reservoir?

Ref: Hydraulic Reservoir Location, Fill Cap ID, Oil Type & Spec

Does the PTO seem to turn on?

Replace Switch

Action: You appear to have a bad LED on the switch. Replace switch, then retest

Ref: Switch replacement procedure & part number

Did you get a ground signal at ECU pin 25 when pressing the switch?

Ref: Download Electrical Schematic – ECU Pin 25

Check Switch and Wiring

Action: Check switch and wiring; if switch tests good, repair wiring

ECU Issue

Action: You may have a bad ECU. Flash software and test, or replace ECU

Fill Reservoir

Action: Fill reservoir with correct hydraulic oil, check for leaks, and retest

Ref: Hydraulic Reservoir Location, Fill Procedure, Oil Spec Sheet

Q5 (MC): What happens when the light goes solid blue?

Q8: Multi-Action Checklist

Action 1: Inspect pump RPM sensor - If pump RPM sensor is not working it will shut off, please inspect pump RPM sensor.

Action 2: Air in lines - There could be air in the lines, please shut off truck and try again.

Action 3: Pump coupling key - If key is out of pump coupling, the pump may not be turning.

Action 4: Check for error codes - If the truck is shutting off it should be generating an error code. Please check display for error codes and follow error code path.

Action 5: Software diagnosis - If it does not show error code, you may need to get EZ TRAC software kit for full diagnosis.

Link: EZ TRAC Software download

Q9.1: Is there 12V at PTO solenoid coil when commanded?

Electrical Circuit Issue

Action: Trace control wiring from ECU to PTO solenoid; repair open or short

Includes: Electrical schematic reference link

Q9.2: Has 12V but PTO Not Engaging

Action 1: Check pilot hose for pinch or crushed fitting

Action 2: Inspect solenoid and replace if needed

Action 3: If solenoid is working with pilot pressure, you may need a new PTO

Q10.1: Does the system remain engaged?

System Not Working

Action: Go back and troubleshoot system not working

System Engaged But No Effort

Action:

1. Check Parameters for wrong settings

2. Check Suction line and filter for clogs or blockage

3. Check to see if the pump sounds normal (No cavitation)

4. Using Startup tool, verify pump health using brake test

If this does not solve it, try more troubleshooting or contact us.

Link: Startup tool