and Answers PDF – Study Guide & Practice Test
2025/2026 Update (Verified Elaborations)
Q: In a TS2 cabinet, how many times can the MMU experience a "Port 1 Fail" in a 24 hour period before
the fault is latched?
Answers
1
Q: On a 2070 MMU monitor unit, how does the field tech program allowable phases?
Answers
Remove diode on program card for allowable phases
Q: On an MMU, is it possible to tape the reset button to prevent the traffic signal from going into flash?
Answers
Yes, it by-passes the conflict feature and will not flash
Q: On a NEMA CMU program card, how does the signal tech program allowable phases?
Answers
Install copper jumpers and soldering them on the program card
Q: According to best maintenance practices, how often should CMU/MMU be tested?
Answers
Annually
,Q: The MMU indicates a RED-FAIL fault on phase 6. Why?
Answers
The load switch/switch pack produces no outputs.
Q: The purpose of the controller CVM (Controller Voltage Monitor) output is to allow the CMU/MMU
to
Answers
monitor the
Controller health
Q: When a Technician is recertifying the CMU/MMU at an intersection, what should the technician do
to have the intersection exit flash?
Answers
Replace the CMU/MMU with a newly tested unit
Q: Absence of all colors on a load switch will be indicated by what fault on an MMU or MMU2?
Answers
Red Fail
Q: Which of the following can be programmed on an MMU to latch after a fault occurs?
Answers
Field check
, Q: How often is an MMU's clock updated from the controller?
Answers
Once a second
Q: In a signal cabinet, on the signal monitor, what does a field check indicate?
Answers
The signal indications don't match the controller output for a phase
Q: A NEMA CMU/MMU uses a program card to tell the monitor which phases are permitted to run
together. Which answer is CORRECT?
Answers
NEMA monitors have wire jumpers missing in all positions, the tech solders the ones in that allow phases
to run together.
Q: When the controller timings DO NOT match the timing sheet, who should be contacted for correct
times?
Answers
Traffic Engineer
Q: An older TS1 cabinet experiences a flash condition but the signal heads are also showing active
green, yellow, and red indications. What is the MOST COMMON issue?
Answers
The mercury contactor is stuck in the normal position.
Q: In a Dual-Ring, 8-phase traffic signal controller, how many phases can run in each ring at the same