TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
22. PRESSURE SENSORS, PS1 / PS2, INOPERATIVE, ERROR CODE(S) 26 AND 27,
(MODEL B ONLY) (continued).
VOLTAGE TEST
(1) Remove three thumb screws and
access cover on right side of vehicle
under front fender to gain access to
cab interrface wiring harness
ACCESS
connector.
COVER
(2) Cut and remove wire ties as necessary
to loosen cab interface wiring harness.
(3) Set multimeter to voltage position.
(4) Turn engine start switch to ON
position.
(5) Place negative (-) probe of multimeter
on known good ground.
(6) Disconnect cab interface wiring
harness connector, (J2) from main
P2
control wiring harness connector, (P2).
J2
(7) Place positive (+) probe of multimeter
on position "2", circuit 1473, of cab
control box connector (J2), Check
multimeter for voltage reading, note
reading.
(8) Place cab digital mode select switch
in "AUTO" position.
(9) Place positive (+) probe of multimeter
on position "3", circuit 1471, of cab
control box connector (J2), note
POSITION
reading.
4
POSITION
NOTE
POSITION
2
3
Position " 4", circuit 1490, should
have a reading of 1-5 volts, not
22-28 volts. If 1-5 volts are not
measured at position "4", replace
the cab digital control box.
(10) Place positive (+) probe of multimeter
on position "4", circuit 1490, of cab
digital control box connector (J2), note
reading.
(11) Turn engine start switch to "OFF"
position.
CABDIGITAL
MODE SELECT
SWITCH
4-44-4.43
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Change 1
