413-01-2
413-01-2
Instrument Cluster
DIAGNOSIS AND TESTING (Continued)
Fuel Gauge
The key ON fueling mode (approximately 90
seconds to read empty [E] to full [F]) requires 3
NOTE: It is critical to follow the pinpoint test
conditions be met:
diagnostic methods to make sure the correct mode is
being used during diagnostics.
•
The transmission is in park (P) (automatic
The instrument cluster receives the fuel level signal
transmissions), or the parking brake applied
from the fuel level sensor, part of the fuel pump
(manual transmissions).
module. The fuel level sensor measures variable
•
The key is in the RUN position.
resistance in the fuel tank depending on the current
•
At least 15 percent of the vehicle’s fuel capacity
fuel level. When the fuel level is low, the
must be added to the fuel tank.
resistance in the unit is low (15 ohms
±
2 ohms).
In key ON fueling mode, a 30 second timer
When the fuel level is high, the resistance in the
activates after the transmission is put into the park
unit is high (160 ohms
±
4 ohms).
(P) position (automatic transmissions) or when the
The instrument cluster uses 4 different operating
parking brake is applied (manual transmissions).
modes to calculate the fuel level:
When the 30 second time has elapsed and at least
•
key OFF fueling
15 percent of the vehicle’s fuel capacity has been
added, the fuel gauge response time is 90 seconds
•
anti-slosh (default mode)
to read from empty (E) to full (F). When the
•
key ON fueling
transmission is shifted out of park (P) or the parking
•
recovery
brake is released, the fuel gauge strategy reverts to
the anti-slosh mode. This mode prevents slow to
After a fuel fill up, the time for the fuel gauge to
read full events from happening if the customer
move from empty (E) to full (F) ranges from 2
refuels the vehicle with the key in the RUN
seconds to 55 minutes depending on which
position.
operating mode the fuel gauge is in.
Recovery mode is incorporated into the instrument
The key OFF fueling mode (2 seconds to read
cluster strategy to recover from a missing fuel level
empty [E] to full [F]) requires 3 conditions be met:
message during a refueling event. Missing fuel level
•
The key must be in the OFF position when
messages result from intermittent opens in the fuel
refueling the vehicle.
sender or its circuits. Recovery mode (empty [E] to
•
At least 15 percent of the vehicle’s fuel capacity
full [F] approximately 20 minutes) is initiated when
must be added to the fuel tank.
the following 2 conditions are met:
•
The instrument cluster must receive a valid key
•
The instrument cluster is in the anti-slosh (default)
ON fuel sender reading within 1 second of the
mode.
key being put into the RUN position. The key ON
•
The actual fuel level in the tank is greater than
sample readings are considered valid if the fuel
what is being displayed by the fuel gauge.
sender reading is between 15 ohms
±
2 ohms and
160 ohms
±
4 ohms. If these conditions are not
Engine Coolant Temperature Gauge
met, the fuel gauge stays in the anti-slosh mode,
Engine coolant temperature information is received
which results in a slow to read full (F) event.
by the instrument cluster from the PCM over the
The default fuel gauge mode is called the anti-slosh
SCP network. Engine coolant temperatures above
mode. To prevent fuel gauge changes from fuel
121
°
C (250
°
F) causes the gauge to indicate above
slosh (gauge instability due to changes in fuel
the normal band. If the engine coolant temperature
sender readings caused by fuel moving around in
information is missing or invalid for 5 seconds, the
the tank), the fuel gauge takes approximately 55
temperature gauge indicates below the cold (C)
minutes to go from full (F) to empty (E).
position.
Voltage Gauge (except Cobra)
The voltage gauge displays the system voltage as
measured at the instrument cluster run input.
2003 Mustang, 8/2002
