TM-9-2320-272-23-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-1 - Page 1273 of 1313
SOLID OVERSPEED WARNING LIGHT - Continued
STEP
1.
IS THERE CONTINUITY BETWEEN SPEED SIGNAL GENERATOR AND ECU CANNON PLUG?
a.
Refer to point to point schematics.
T0457DAA
CTIS AMBER
WARNING LIGHT
HWY
(HIGHWAY)
X - C
RUN FLAT
ECU
SAND
SPEED SIGNAL
GENERATOR
TRANSFER
CASE
EMER
(EMERGENCY)
Figure 1.
Speed Signal Generator and ECU.
b.
Check connection of electrical lead at speed signal generator on pneumatic controller. Clean and tighten
as needed.
CAUTION
Turn battery switch to OFF position before disconnecting or connecting ECU wiring
harness. Failure to do so may result in damage to ECU.
c.
Turn battery switch to OFF position.
d.
Disconnect CTIS wiring harness cannon plug at ECU.
e.
Disconnect electrical lead at signal generator.
f.
Set multimeter to measure resistance.
g.
Connect multimeter red lead to signal generator lead of wiring harness.
h.
Connect multimeter black lead to harness connector at ECU cannon plug.
i.
Meter reading should be less than 200 ohms.
CONDITION/INDICATION
IS THERE CONTINUITY BETWEEN SPEED SIGNAL GENERATOR AND ECU CANNON PLUG?
DECISION
YES - Go to Step (2).
NO - Replace faulty CTIS wiring harness (Volume 2, WP
0322). Go to Step (3) to verify problem is solved.
TM 9-2320-272-23-1
0151
0151-2
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