Etc Indicator Description - Dodge dakota 2002 Service Manual

8J - 24 INSTRUMENT CLUSTER
ENGINE TEMPERATURE GAUGE (Continued)
the cluster from the Powertrain Control Module
(PCM) on vehicles equipped with a gasoline engine,
or from the Engine Control Module (ECM) on vehi-
cles equipped with a diesel engine over the Program-
mable Communications Interface (PCI) data bus. The
engine coolant temperature gauge is an air core mag-
netic unit that receives battery current on the instru-
ment cluster electronic circuit board through the
fused ignition switch output (run-start) circuit when-
ever the ignition switch is in the On or Start posi-
tions. The cluster is programmed to move the gauge
needle back to the low end of the scale after the igni-
tion switch is turned to the Off position. The instru-
ment cluster circuitry controls the gauge needle
position and provides the following features:
• Engine Temperature Message - Each time
the cluster receives a message from the PCM or ECM
indicating the engine coolant temperature is between
the low end of normal [about 54° C (130° F) for gas-
oline engines, or about 60° C (140° F) for diesel
engines] and the high end of normal [about 122° C
(252° F) for gasoline engines, or about 116° C (240°
F) for diesel engines], the gauge needle is moved to
the actual relative temperature position on the gauge
scale.
• Engine Temperature Low Message - Each
time the cluster receives a message from the PCM or
ECM indicating the engine coolant temperature is
below the low end of normal [about 54° C (130° F) for
gasoline engines, or about 60° C (140° F) for diesel
engines], the gauge needle is held at the graduation
on the far left end of the gauge scale. The gauge nee-
dle remains at the left end of the gauge scale until
the cluster receives a message from the PCM or ECM
indicating that the engine temperature is above
about 54° C (130° F) for gasoline engines, or about
60° C (140° F) for diesel engines, or until the ignition
switch is turned to the Off position, whichever occurs
first.
• Engine Temperature High Message - Each
time the cluster receives a message from the PCM or
ECM indicating the engine coolant temperature is
above about 122° C (252° F) for gasoline engines, or
about 116° C (240° F) for diesel engines, the gauge
needle is moved into the red zone at the far right end
of gauge scale, the check gauges indicator is illumi-
nated, and a single chime tone is sounded. The gauge
needle remains in the red zone and the check gauges
indicator remains illuminated until the cluster
receives a message from the PCM or ECM indicating
that the engine temperature is below about 122° C
(252° F) for gasoline engines, or about 116° C (240°
F) for diesel engines, or until the ignition switch is
turned to the Off position, whichever occurs first.
The chime tone feature will only repeat during the
same ignition cycle if the check gauges indicator is
cycled off and then on again by the appropriate
engine temperature messages from the PCM or ECM.
• Communication Error - If the cluster fails to
receive an engine temperature message, it will hold
the gauge needle at the last indication for about five
seconds or until the ignition switch is turned to the
Off position, whichever occurs first. After five sec-
onds, the cluster will move the gauge needle to the
low end of the gauge scale.
• Actuator Test - Each time the cluster is put
through the actuator test, the engine coolant temper-
ature gauge needle will be swept to several calibra-
tion points on the gauge scale in a prescribed
sequence in order to confirm the functionality of the
gauge and the cluster control circuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the engine coolant temperature
sensor to determine the engine operating tempera-
ture. On vehicles with a diesel engine, the ECM con-
tinually monitors the engine coolant temperature
sensor to determine the engine operating tempera-
ture. The PCM or ECM then sends the proper engine
coolant temperature messages to the instrument
cluster. For further diagnosis of the engine coolant
temperature gauge or the instrument cluster cir-
cuitry that controls the gauge, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the check gauges indicator due to a high engine tem-
perature gauge reading, it may indicate that the
engine or the engine cooling system requires service.
For proper diagnosis of the engine coolant tempera-
ture sensor, the PCM, the ECM, the PCI data bus, or
the electronic message inputs to the instrument clus-
ter that control the engine coolant temperature
gauge, a DRBIII scan tool is required. Refer to the
appropriate diagnostic information.
ETC INDICATOR
DESCRIPTION
An Electronic Throttle Control (ETC) indicator is
standard equipment on all gasoline engine instru-
ment clusters. However, on vehicles not equipped
with the optional 5.7 liter gasoline engine, this indi-
cator is electronically disabled. The ETC indicator is
located on the right side of the instrument cluster, to
the right of the engine temperature gauge. The ETC
indicator consists of a stencil-like cutout of the Inter-
national Control and Display Symbol icon for "Elec-
tronic Throttle Control" in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. A red Light Emit-
ting Diode (LED) behind the cutout in the opaque
DR