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.
235
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
Solenoid System Option:
In-cab Cortex Display does
not indicate the fuel level
correctly or an alarm is
activated on the Cortex
Display indicating
"Transducer-# Unplugged/
Short Check Sensor and
Wiring" Fail for a given
Tank#.
The fuel cylinder pressure
transducer or the
interconnecting wiring may
be defective.
Confirm that the 3pin electrical
connector at the transducer is
connected and place the
vehicle's ignition switch in the
"Run" position. Use a voltmeter
to read:
Voltage between connector
positions A (BRN) and B
(BLK). The voltage should be
approximately 12 vdc.
Voltage between connector
positions B (BLK) and C
(YEL). The voltage should be
between 0.5 to 5.0 vdc.
*If the voltage across A
and B is 0 or significantly
below battery voltage,
there is a problem with the
vehicle's wiring not
supplying power to the fuel
module's pressure
transducer.
*If the voltage across B
and C is either 0 or 5.5
vdc, the fuel tank's
pressure transducer is
most likely defective. Call
866-310-4345 for technical
assistance.
*If the voltage across B
and C is between 0.5 to
5.0 vdc then the fuel
module's pressure
transducer is operating
correctly. The problem is
likely in the Cortex Display
or the Cortex Controller.
*If the problem cannot be
resolved, call 866-310-
4345 for technical
assistance.