IMSA TRAFFIC SIGNAL TECHNICIAN I EXAM
PREP STUDY GUIDE 2026 WITH VERIFIED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
◉On a 2070 MMU monitor unit, how does the field tech program
allowable phases? Ans: Remove diode on program card for allowable
phases
◉On an MMU, is it possible to tape the reset button to prevent the
traffic signal from going into flash? Ans: Yes, it by-passes the conflict
feature and will not flash
◉On a NEMA CMU program card, how does the signal tech program
allowable phases? Ans: Install copper jumpers and soldering them on
the program card
◉According to best maintenance practices, how often should
CMU/MMU be tested? Ans: Annually
◉The MMU indicates a RED-FAIL fault on phase 6. Why? Ans: The
load switch/switch pack produces no outputs.
,◉The purpose of the controller CVM (Controller Voltage Monitor)
output is to allow the CMU/MMU to
monitor the Ans: Controller health
◉When a Technician is recertifying the CMU/MMU at an intersection,
what should the technician do to have the intersection exit flash? Ans:
Replace the CMU/MMU with a newly tested unit
◉Absence of all colors on a load switch will be indicated by what fault
on an MMU or MMU2? Ans: Red Fail
◉Which of the following can be programmed on an MMU to latch after
a fault occurs? Ans: Field check
◉How often is an MMU's clock updated from the controller? Ans:
Once a second
◉In a signal cabinet, on the signal monitor, what does a field check
indicate? Ans: The signal indications don't match the controller output
for a phase
◉A NEMA CMU/MMU uses a program card to tell the monitor which
phases are permitted to run together. Which answer is CORRECT? Ans:
, NEMA monitors have wire jumpers missing in all positions, the tech
solders the ones in that allow phases to run together.
◉When the controller timings DO NOT match the timing sheet, who
should be contacted for correct
times? Ans: Traffic Engineer
◉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? Ans: The mercury contactor is stuck in the
normal position.
◉In a Dual-Ring, 8-phase traffic signal controller, how many phases can
run in each ring at the same
time? Ans: 1
◉Observations indicate that vehicles are being detected in one lane and
that this is shown on the detection interface unit. However, the controller
does not show any detection for that phase. This could be caused by
Ans: Improper detection phase assignment programming in the
controller
◉As soon as vehicles leave the detection zone of an approach that has
met its minimum green time, a signal immediately goes to yellow from
PREP STUDY GUIDE 2026 WITH VERIFIED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
◉On a 2070 MMU monitor unit, how does the field tech program
allowable phases? Ans: Remove diode on program card for allowable
phases
◉On an MMU, is it possible to tape the reset button to prevent the
traffic signal from going into flash? Ans: Yes, it by-passes the conflict
feature and will not flash
◉On a NEMA CMU program card, how does the signal tech program
allowable phases? Ans: Install copper jumpers and soldering them on
the program card
◉According to best maintenance practices, how often should
CMU/MMU be tested? Ans: Annually
◉The MMU indicates a RED-FAIL fault on phase 6. Why? Ans: The
load switch/switch pack produces no outputs.
,◉The purpose of the controller CVM (Controller Voltage Monitor)
output is to allow the CMU/MMU to
monitor the Ans: Controller health
◉When a Technician is recertifying the CMU/MMU at an intersection,
what should the technician do to have the intersection exit flash? Ans:
Replace the CMU/MMU with a newly tested unit
◉Absence of all colors on a load switch will be indicated by what fault
on an MMU or MMU2? Ans: Red Fail
◉Which of the following can be programmed on an MMU to latch after
a fault occurs? Ans: Field check
◉How often is an MMU's clock updated from the controller? Ans:
Once a second
◉In a signal cabinet, on the signal monitor, what does a field check
indicate? Ans: The signal indications don't match the controller output
for a phase
◉A NEMA CMU/MMU uses a program card to tell the monitor which
phases are permitted to run together. Which answer is CORRECT? Ans:
, NEMA monitors have wire jumpers missing in all positions, the tech
solders the ones in that allow phases to run together.
◉When the controller timings DO NOT match the timing sheet, who
should be contacted for correct
times? Ans: Traffic Engineer
◉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? Ans: The mercury contactor is stuck in the
normal position.
◉In a Dual-Ring, 8-phase traffic signal controller, how many phases can
run in each ring at the same
time? Ans: 1
◉Observations indicate that vehicles are being detected in one lane and
that this is shown on the detection interface unit. However, the controller
does not show any detection for that phase. This could be caused by
Ans: Improper detection phase assignment programming in the
controller
◉As soon as vehicles leave the detection zone of an approach that has
met its minimum green time, a signal immediately goes to yellow from
