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JX
DIAGNOSIS AND TESTING (Continued)
If minimum amperage could not be met, refer to
the appropriate Powertrain Diagnostic Procedures
manual for testing.
BATTERY TEMPERATURE SENSOR
To perform a complete test of this sensor and its
circuitry, refer to the appropriate Powertrain Diag-
nostic Procedures manual. To test the sensor only,
refer to the following:
(1) Disconnect the sensor from the engine harness.
(2) Attach ohmmeter leads to the wire terminals of
the sensor.
(3) At room temperature of 25° C (75–80° F), an
ohmmeter reading of 9K to 11K ohms should be
observed.
(4) If reading is above or below the specification,
replace the sensor.
(5) Refer to the Removal and Installation section
for procedures.
ON-BOARD DIAGNOSTIC SYSTEM TEST
GENERAL INFORMATION
The Powertrain Control Module (PCM) monitors
critical input and output circuits of the charging sys-
tem, making sure they are operational. A Diagnostic
Trouble Code (DTC) is assigned to each input and
output circuit monitored by the OBD system. Some
circuits are checked continuously and some are
checked only under certain conditions.
If the OBD system senses that a monitored circuit
is bad, it will put a DTC into electronic memory. The
DTC will stay in electronic memory as long as the
circuit continues to be bad. The PCM is programmed
Diagnostic Trouble Code
12*
41**
46**
47**
55*
*Check Engine lamp will not illuminate at all times if this Diagnostic Trouble Code was recorded. Cycle igni-
tion key as described in manual and observe code flashed by Check Engine lamp.
**Check Engine lamp will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
DRB Scan Tool Display
Battery Disconnect
Generator Field Not Switching
Properly
Charging System Voltage Too High
Charging System Voltage Too Low
N/A
Fig. 7 Generator Diagnostic Trouble Code
to clear the memory after 50 engine starts if the
problem does not occur again.
DIAGNOSTIC TROUBLE CODES
Diagnostic Trouble Codes (DTC) are two-digit num-
bers flashed on the malfunction indicator (Check
Engine) lamp that identify which circuit is bad. Refer
to Group 25, On Board Diagnostic for more informa-
tion. A DTC description can also be read using the
DRB scan tool. Refer to the appropriate Powertrain
Diagnostic Procedures manual for information.
A DTC does not identify which component in a cir-
cuit is bad. Thus, a DTC should be treated as a
symptom, not as the cause for the problem. In some
cases, because of the design of the diagnostic test
procedure, a DTC can be the reason for another DTC
to be set. Therefore, it is important that the test pro-
cedures be followed in sequence, to understand what
caused a DTC to be set.
See the Generator Diagnostic Trouble Code chart
(Fig. 7) for DTC's which apply to the charging sys-
tem. Refer to the Powertrain Diagnostic Procedures
manual to diagnose an on-board diagnostic system
trouble code.
RETRIEVING DIAGNOSTIC TROUBLE CODES
To start this function, cycle the ignition switch ON-
OFF-ON-OFF-ON within 5 seconds. This will cause
any DTC stored in the PCM memory to be displayed.
The malfunction indicator (Check Engine) lamp will
display a DTC by flashing on and off. There is a
short pause between flashes and a longer pause
between digits. All DTC's displayed are two-digit
numbers, with a four-second pause between codes.
Description of Diagnostic Trouble Code
Direct battery input to PCM was
disconnected within the last 50 key-on
cycles.
An open or shorted condition detected in
the generator field control circuit.
Battery voltage sense input above target
charging voltage during engine operation.
Battery voltage sense input below target
charging during engine operation. Also, no
significant change detected in battery
voltage during active test of generator
output.
Completion of fault code display on Check
Engine lamp.
CHARGING SYSTEM
8C - 9
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