TM 9-6115-729-24
0013
ELECTRONIC TECHNICIAN (ET) TROUBLESHOOTING - Continued
CORRECTIVE ACTION - Continued
e. Run the Air Inlet Heater Override on the Cat ET and observe the voltmeter.
NOTE
The Air Inlet Heater Override has a one minute timer in order to disable the test when the time
expires.
f.
If the voltmeter does not measure 24 +/- 3.0 Vdc, repair/replace the wire
between the air inlet heater relay and the air inlet heater (WP 0090), after
power is removed from the ECM.
g. Stop the Air Inlet Heater Override.
h. On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
i.
Reconnect the wire between the air inlet heater relay and the air inlet heater.
j.
Verify that the repair eliminates the problem.
STEP 12.
If the problem is not resolved, measure the current through the air inlet heater.
a. Connect a 155-5176 AC/DC current probe or an equivalent inductive pickup
clamp around wire between the air inlet heater relay and the air inlet heater.
b. Connect the current probe to a multimeter.
c.
Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
d. Run the Air Inlet Heater Override on the Cat ET and observe the current
reading on the multimeter. Verify the current is within the specified range of
between 77 and 95 Amperes.
CAUTION
Do not leave the Air Inlet Heater Override ON. Avoid unnecessary cycling of the air inlet heater in
order to prevent the battery from discharging. The Air Inlet Heater Override has a one minute
timer that disables the test when the time expires.
e. Stop the Air Inlet Heater Override.
f.
On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
g. If the current is not within the specified range, check continuity of the wire
between the air inlet heater and engine ground. Check the connections at the
air inlet heater and at engine ground for corrosion. If the wire between the air
inlet heater and engine ground is OK, replace the air inlet heater (WP 0103).
STEP 13.
Verify the problem has been resolved.
0013-10
