Instrument Reset and Diagnostics
Members of the Confidential List have discovered for themselves
a very useful little trick using the instrument panel Odometer trip button.
Using the List and sharing information about their own experimentation, a
complete list of the diagnostic capabilities developed.
It all began one chilly evening late in December 2001. We were
operating on a temporary list at the time because of a server problem, and a
member, Robert, posted a problem with his instruments
reading only half on cold
damp days. Rob agreed that he had the same thing occasionally, and I
had also experienced the same phenomena. I posted the Instrument Panel Reset,
which is to press the odometer reset button for about 5 seconds, while the
engine is running. This puts the instrument panel into self-diagnostic mode
during which all the bulbs in the displays light up and the needles rise and
fall.
On New Years Day Pete then posted one stage further. He had
noticed when trying his that the instrument panel then goes through a list of
inputs by repeatedly pressing the reset button. Some values were self
explanatory - others still a mystery.
The List was quiet again on this subject until 30th January 2002,
when Edward posted a problem with his 2.3 1998 Scorpio. With our better
knowledge today we would have been quicker at coming to a solution, but at the
time his experience of climate control computer resetting with low/high voltage
errors were a bit more of a puzzle. Of course it turned out that his battery had
failed and was easily fixed, but Bill posted the trick of the reset button so
that Ed could check his system voltage. This remains a very useful use for the
instrument reset. Why fiddle about with a voltage meter when you can check it
from the instrument panel?
Fredrik then asked what the more obscure codes meant. He had
figured out most of them but others, like rEL1, rEL2 and button
remained a mystery for a while longer..
In February Biggles asked again what the more obscure values
were, and by this time John B had obviously experimented, because he filled in
the missing blank posed by the 'button' value, which gives the value of
the button pressed on the trip computer.
Then Tim came up with another gem. He noticed that the engine
temperature value was 255 at cold, and that the value fell as the engine
temperature increased. Since the engine temperature sensor returned a voltage in
inverse proportion to its temperature, he argues that 255 is the cold value, and
that a 132 value of a hot engine was not actually a real temperature but a
decimal value which is read by the PCM.
Alex Z gave us the Type for his DOHC2000 16V - 02.
Then Nick mailed me to say he'd looked at his. He gives us
the code for the 2.3L - 03. He ran his cold and warm and checked the readings
and noted that the rAE reading changed slightly after a short run - from 23.7 to
23.0. Could this be average fuel consumption - yes, but for the Range to
Empty calculation - see later.
In May Damian filled in the blank for the 12V - 19, while John
gave us the code for his 1997 24V Scorpio - 11. Does this mean there was an
instrument upgrade at some time?
In June Peter sent in the Type for his TDI, 07.
In March 2004, Alan S gave us the rAE , the calculated
consumption figure for the Range to Empty. Thanks Alan.
In September 2004 Chris S contacted us with amended ideas for
FLO and PULSES, and at last gave us the answer for LO S and
LO C! The LO C is the resistance
of the Low Coolant circuit, and LO S that of the Screenwash. Both
sensors have an integral resistor and the normal (closed) state reads approx 20.
Further, he states that in January 1997 when Ford deleted the coolant level
sensor they shorted the connection, so these models may show LO C S-C
(short-circuited)
Finally in October 2004
the last pieces of the jigsaw were slotted in by Pete C. The following is the
entire test sequence with the proper responses for the Scorpio Instrument
Cluster. Starting with holding the reset button down for 5 seconds, each press
of the button starts the next test. If the button is not pressed for 30 seconds
then the test sequence is abandoned.
From start to finish
this process of discovery has taken almost 3 years - but we got there in the
end!
1.
Type - Type of Instrument Cluster:
0 4 cylinder petrol, low series, km
1 4 cylinder petrol, low series, mph
2 4 cylinder petrol, high series, km
3
4 cylinder petrol, high series, mph
4 4 cylinder diesel, low series, km
5 4 cylinder diesel, low series, mph
6 4 cylinder
diesel, high series, km
7
4 cylinder diesel, high series, mph
8 6 cylinder
24V petrol, low series, km
9 6 cylinder
24V petrol, low series, mph
10 6 cylinder
24V petrol, high series, km
11
6 cylinder 24V petrol, high series, mph
12
6 cylinder diesel, low series, km (not installed on Scorpio)
13 6 cylinder diesel, low series, mph
(not installed on Scorpio)
14 6 cylinder
diesel, high series, km (not installed on Scorpio)
15
6 cylinder diesel, high series, mph (not installed on Scorpio)
16 6 cylinder
12V petrol, low series, km
17 6 cylinder
12V petrol, low series, mph
18 6 cylinder
12V petrol, high series, km
19
6 cylinder 12V petrol, high series, mph
Check that the
instrument panel displays the correct instrument code. An incorrect Type code
can mean that the instrument panel has been changed.
| 2. Speed |
Vehicle speed sensor. Shows the actual speed of the vehicle
in KPH. This should be within +5% of the
MPH. |
| 3. Pulses |
Shows the input frequency of the
engine speed sensor, updated every second. This check allows the engine
speed signal coming from the alternator, (12V V6, 2.5 TDi) or the EDIS (all
others) to be measured and calibrated. Should show the following numbers at
idle:
26 for 4 cylinder DOHC
40 for 6 cylinder 24V
52 for diesel types
200 for 6 cylinder 12V |
| 4. Fuel |
Fuel level in approximate litres.
Full should indicate 65 to 69
litres
O-C means open circuit - break in
wiring connection with the fuel level sensor
S-C wiring connection
short-circuited. |
| 5. En9 t |
This checks the engine coolant
temperature sensor as a data signal between 20 to 255, disproportionate to
temperature (i.e., high temp, low data number)
S-C means sensor is out of normal
range.
When the temperature gauge needle
is horizontal the display should read between 79 to 129
37 Maximum
temperature
57 Bottom of
red chaplet
79 to 159 Middle of Normal
band
242
Middle of blue chaplet
255
Bottom |
| 6. rEL 1 |
Tests that the ROM software release of the microprocessor is
in the range of 0-999. This validates the processor function and should be a
steady display.
If the number displayed is flashing then all functions of
the cluster could be incorrect and the entire cluster must be replaced. |
| 7. rEL 2 |
Tests that the Non Volatile Memory (NVM) software release
level is in the range of 0-255. This validates the NVM and should be a steady
display.
If the number displayed is flashing then all functions of the
cluster could be incorrect and the entire cluster must be replaced.
NOTE: If the vehicle being tested is a police vehicle, it is normal
for rEL 2 to flash. |
| 8. bAtt |
This mode checks the IGN voltage
to the instrument panel. It does not check the battery connection to the
cluster.
If the number displayed is an
acceptable voltage then proceed to next test.. |
| 9. Air t |
Tests the external air temperature sensor and connections.
It shows the air temperature directly in Fahrenheit.
O-C is open circuit
or less than -40F
S-C is short circuit or greater than 150F.
NOTE: this reading will not be the same as that displayed by the trip
computer, the latter being corrected for possible heating of the sensor by
the engine. |
| 10. FL0 |
This mode tests the EECV and
connections for fuel flow. The number displayed increments by one for every
10 fuel pulses received by the instrument cluster from the EECV since
entering the feature. At 6553 the display will return to zero.
With IGN on and engine off (KOEO)
the FLO should read zero (0). Start the engine and the FLO number should
increment from 0 to 6553. If it does not it indicates a signal or loom
fault. NOTE: starting the engine will abort the test sequence - press the
button for 5 seconds again and press the button repeatedly to return to the
FL0 test. |
| 11. rAE |
Running Average Economy. This
figure represents an internal value of the average economy in MPG, from
which the Range to Empty is calculated. The figure will be low after periods
of extended idle etc and high after part-throttle cruising.
If an acceptable MPG figure is
displayed continue to the next check.
If an unacceptable number is
displayed this indicates a cluster fault. |
| 12. button |
This test checks the fuel computer button resistance inputs
and loom connections. Each number represents a range value for each single
button pressed. 255
No button pressed
208 to 241 MODE only
pressed
38 to 56
S only pressed
158 to 185 R only pressed.
If the display shows 255 when any
button is pressed a wiring fault is indicated, or the button contacts inside
the fuel computer may be dirty and require cleaning.
if the display shows a number
less than 38 when any button is pressed this indicates a wiring fault. |
| 13. L0 C |
Low coolant sensor. This shows
the value of the input, or S-C for a short circuit.
Reading 5-33 are normal readings.
The low coolant warning lamp
should turn off after 5 seconds after starting. If this lamp extinguishes
after starting then the LO C should show between 5 to 33. If the lamp stays
on the value of the LO C should be higher than 33. If otherwise check wiring
and sensor operation.
Note - late models where the
coolant level sensor was deleted will show S-C |
| 14. L0 S |
Low screen-wash fluid sensor. This
shows the value of the input, or S-C for a short circuit.
Reading 5-33 are normal readings.
The low washer warning lamp
should turn off after 5 seconds after starting. If this lamp extinguishes
after starting then the LO C should show between 5 to 33. If the lamp stays
on the value of the LO C should be higher than 33. If otherwise check wiring
and sensor operation.
Note - late models where the
washer level sensor was deleted will show S-C |
