Dodge ZB 2005 Service Manual page 1394

3.9.3 SYSTEM REVISIONS
The 2005 ZB HVAC System remains mostly car-
ryover from 2004.
3.9.4 SYSTEM DIAGNOSTICS
Fault detection is through active and stored Diag-
nostic Trouble Codes (DTCs)
•
DTCs are displayed by the DRBIII .
• Active DTCs are those which currently exist in
the system. The condition causing the fault must
be repaired in order to clear this type of DTC.
• Stored DTCs are those which occurred in the
system since the A/C-Heater Control Module re-
ceived the last ''clear diagnostic info'' message.
A/C Performance Testing:
• The A/C system uses a cycling clutch switch for
freeze protection. Refer to the ZB/SRT-10 Service
Manual for A/C Performance Testing procedures.
The HVAC Door Recalibration function:
• is actuated with the DRBIII .
• monitors for door span faults.
•
faults display on the DRBIII as test messages
only after running the test.
• faults will not display on the DRBIII as Diag-
nostic Trouble Codes.
•
will cause the EBL mode switch status indicator
to flash while the test is running.
If the test fails, the status indicator will continue
to flash until either the test returns passed or the
ignition key is cycled. It will also prevent the A/C
mode switch status indicator from indicating A/C
operating status. However, the A/C mode switch
will continue to function in this state.
The Actuator Circuit Test:
• is actuated with the DRBIII .
• monitors for shorted actuator circuits.
• allows service to easily diagnose and troubleshoot
up to three simultaneous shorts.
• supplements the continuous diagnostics on the
actuator drive system.
•
faults display on the DRBIII as test messages
only after running the test.
• faults will not display on the DRBIII as Diag-
nostic Trouble Codes.
When Performing The Actuator Circuit Test
GENERAL INFORMATION
CAUTION: To ensure a proper diagnosis,
repair all Short Too Complex messages first,
all common door driver circuit related
messages second, and all other door driver
circuit related messages last.
CAUTION: The DRBIII
three Actuator Circuit Test messages at a
time. After repairing each Actuator Circuit
Test message, cycle the ignition switch, then
rerun the Actuator Circuit Test to ensure no
new messages exist.
• The Short Too Complex message:
indicates that a specific determination of which
lines are shorted could not be made.
is caused by more than three drivers being
shorted in the same direction. For example, four
drivers all shorted to ground, or two or more
drivers shorted with at least one driver shorted
to ignition/battery and one driver shorted to
ground.
•
Messages displaying:
XXX Driver/Circuit Shorted to Ignition/Battery
will set on a per-driver basis.
XXX Driver/Circuit Shorted to Ground will set on
a per-driver basis.
the same two drivers/circuits shorted to ignition/
battery as-well-as shorted to ground indicates
that two actuator driver circuits are shorted
together.
•
When the test returns passed then troubleshoot-
ing should proceed to clearing faults and running
the HVAC Door Recalibration system test as a
final check of system health.
3.10 INSTRUMENT CLUSTER / GAUGE
CLUSTER
The Instrument Cluster houses the Fuel Gauge,
Speedometer with LCD odometer, and the Tachom-
eter. The Gauge Cluster houses the Engine Oil
Pressure Gauge, Engine Oil Temperature Gauge,
Engine Coolant Temperature Gauge, and the Volt-
meter.
The cluster positions all of the analog gauges
using PCI bus messages received from the BCM,
CAB, ACM and the PCM. Warning indicators are
located in the Instrument Cluster and the Gauge
Cluster. Most warning indicators are controlled by
the cluster in response to PCI bus messages. Some
indicators are cluster controlled based on gauge
pointer position. The Instrument Cluster dimming
is controlled via PCI bus messages received from
13
can display up to