Dover HEIL Command-SST - CNG Fuel System Troubleshooting (Continued)

Issued June 2020
Compressed Natural Gas (CNG) Option
Copyright 2020, Heil Environmental
Printed in U.S.A.
232
CNG FUEL SYSTEM TROUBLESHOOTING (CONTINUED)
The following table lists possible problems, along with causes, corrections, and results.
PROBLEM OBSERVED
POSSIBLE CAUSES
CORRECTIVE/
DIAGNOSTIC ACTIONS
RESULTS AND OTHER
ACTIONS
Vehicle's starter will not
operate.
Interrupt door switch signal
is not being properly
recognized by the vehicle.
Disconnect the 12-pin
electrical connector at the
rear of the fuel module. Use
an ohm meter or continuity
tester across pins (GRN)
and 10 (YEL) of the fuel
module side of the
connector (female
connector).
Press and release the fuel
module interrupt door
switch. When the switch is
depressed, there should be
continuity between pins 9
(GRN) and 10 (YEL).
Continuity should be lost
when the switch is released.
If operation of the door
switch makes and breaks
continuity as described, and
the starter will not operate,
there is most likely a
problem in the vehicle's
wiring.
If the operation of the door
switch does NOT make or
break continuity as
described, there is most
likely a wiring problem in the
fuel module.
If the problem cannot be
resolved, call 866-310-4345
for technical assistance.