TM 9-6115-729-24
0013
ELECTRONIC TECHNICIAN (ET) TROUBLESHOOTING - Continued
CORRECTIVE ACTION - Continued
c.
Connect a voltmeter between the wire at the air inlet heater and engine
ground.
d. Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to
NORMAL. On EMCP set ENGINE CONTROL switch to COOL
DOWN/STOP.
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, 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 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
77 A to 95 A.
NOTE
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 in order to disable 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.
0013-6
