Snap-on EAZ0025B02B Error $21: No main shaft speed signal (M-Shaft)

Diagnostic tool software · taken from the manufacturer’s manual, pages cited

Error code$21

Main shaft speed signal is not being received. The manual lists no action for this code.

Model
Snap-on EAZ0025B02B
Display shows
No main shaft speed signal (M-Shaft) ($21)
Type
Error code
Source
Manual p. 427

What $21 means

No main shaft speed signal (M-Shaft) p. 427

If $21 is still not resolved

  • contact service / dealer p. 174
    “CAUTION: YOU MUST READ TROUBLE CODES BEFORE SELECTING FUNCTIONAL TESTS OR CODES CAN BE LOST.”
Open the manual at page 427 All EAZ0025B02B error codes Manual details & download

This page summarises what the manufacturer’s manual says about $21; each statement links to the page it comes from, and quoted lines are copied word for word. It is not a substitute for the manual or for a qualified installer. ManualLib is not affiliated with Snap-on. Found a mistake? Report an error.