Control Modules—Network Control Module 200 Series 43
200TC29
Rear View
of Battery
Submodule
(+)
(-)
Figure 29: Measuring the Voltage of the Battery
-
If the voltage is low, ensure that the battery is charged. A
charging period of at least 15 minutes provides an accurate
open circuit voltage reading.
-
If the battery fails the open circuit test, perform the preliminary
battery charger test (Step 2). If the charger is good, replace the
battery submodule.
-
If the battery submodule passes the open circuit test, low
capacity may prevent it from adequately backing up the NCM’s
memory. Perform the loaded battery test (Step 3).
2.
Battery Charger (preliminary)
A defective charger may not provide full battery capacity; in severe
cases, it could actually drain the battery. A preliminary test of the
charger is as follows:
•
While maintaining power to the NCM, remove the battery submodule.
•
From within the NCM, extract the cable that connects to the
battery submodule.
•
Locate Pin 1 on the connector. It is marked by the arrow-shaped
triangle on the latching side of the connector. The wire is red on
the NCM.
•
Measure the open circuit voltage across Pins 1 and 2 (Pin 1 is
positive). If the charging circuit is good, the voltage should read
between 7 and 8 VDC.
Failing the preliminary charger test indicates a charger failure.
Replace the NCM. (Replace the battery submodule if the charger
passed this test and the battery failed its open circuit test.)
The charger may, however, pass the preliminary test but still not
adequately charge the battery submodule. If the battery and charger
pass their preliminary tests, apply the more extensive tests that follow.
