Chrysler 300M 2002 Service Manual page 1642

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HEATING & AIR CONDITIONING (Continued)
Fig. 1 ENTERING SELF-DIAGNOSTIC MODE
1 - PRESS BUTTONS SIMULTANEOUSLY
diagnostic mode while the engine is running and the
vehicle is not moving. To place the system into it's
diagnostic mode, adjust the MTC to the following set-
tings: (Fig. 2)
(1) The engine must be running with vehicle not
moving.
(2) The Fan Speed set to any speed except OFF.
(3) The Temperature Knob in full cold (full coun-
terclockwise position).
(4) The mode knob must be placed in defrost posi-
tion (full clockwise position).
(5) The A/C button can be ON or OFF.
(6) Press and hold the EBL button until the
Mechanical Instrument Cluster Odometer display
indicates an "AC00". The body control module (BCM)
will chime once and the MTC A/C button LED will
begin blinking.
(7) Release the EBL button and wait until the
MTC A/C button LED stops blinking. This means
that the error check and climate control unit door
calibration is complete.
Fig. 2 MTC CONTROL HEAD
HEATING & AIR CONDITIONING 24 - 5
Diagnostic trouble codes related to the MTC head
and the climate control unit will appear on the odom-
eter display in numerical form after the letters "AC".
The diagnostic trouble codes are stored in the BCM
and can range between 23 and 51. The odometer dis-
play will return to normal operation if no trouble
codes are found. If a problem is found, then the
odometer will display the letters "A/C" followed by
the trouble code number. The odometer display can
only show one diagnostic trouble code at a time.
Under certain circumstances, more than one diagnos-
tic trouble code could be in the memory. To scroll
through any additional diagnostic trouble codes,
press the A/C button on the MTC head. The BCM
will beep each time the A/C button is pushed. Con-
tinue pushing the A/C button and recording the trou-
ble code numbers until the odometer returns to
normal operation (note the letters AC will disappear).
It is important that no other knob or button is
pushed until all codes are read. Pushing any
button except the A/C button or turning a knob
will end the diagnostic test without showing
the rest of the trouble codes. There also may be
other trouble codes stored in the BCM not
related to the Climate Control System. These
codes can only be found using the DRBIII scan
tool.
ERASING DIAGNOSTIC TROUBLE CODES (DTC's)
Diagnostic trouble codes can be cleared from the
memory two ways:
• The DRBIII scan tool
• Power to the BCM can be disconnected for ten
minutes by disconnecting the battery negative
remote cable.
If the scan tool is to be used, refer to the Appropri-
ate Diagnostic Information.
CAUTION: Fault code 26 can be created if the in-car
sensor thermistor is disconnected while the BCM is
operating. This can happen by disconnecting con-
nectors from the BCM or the ATC Control Head
when the battery is connected (even if the ignition
switch is OFF). To correct, clear the fault code 26
from the BCM.