Boo-yah!
The message center also has a built-in self diagnostic
setting. To access it, just hold down the RANGE and COMPASS
switches while turning the ignition switch from OFF to RUN.
Press RANGE to advance the message center indicator module to
the next test group.
Cycle the ignition from RUN to OFF and back to RUN to return
to normal operation.
Now here's what you get when you press RANGE:
1. ROM Level and check sum test. This gives the software build
(actually firmware number when it was installed (not a big
deal)) but the check sum has to be 00 (zero, zero). If it is
not, then replace the message center.
2. EEPROM Level and Check Sum Test. Same as above. The EEPROM
should have a check sum of 0000 (zero, zero, zero, zero). If
not, replace the message center.
3. Display Test. This test displays the same character in all
24 character positions. Press VEHICLE SETTINGS or TRIP ODO
buttons to sequence through the entire character set. Replace
the message center if the characters are not displayed
properly.
4. Lamp Test. This test lights each one of the warning
indicators that the message center indicator module drives
(FASTEN SEAT BELT, O/D OFF, and TRACTION CONTROL OFF) in
sequence. To sequence through the indicators, press the TRIP
ODO button.
Test 1 illuminates the fasten seat belt indicator.
Test 2 - 6 are inactive and produce no output.
Test 7 illuminates the traction control off indicator.
Test 8 illuminates the O/D off indicator.
5. FINAL DATE. This is a coded date that indicates when the
message center module was manufactured and is used by the
dealer when requesting assistance from the "hotline"
(figure that one out!)
6. SERIAL NUMBER (duh?)
7. A/D CHANNEL TESTS. (Analog to Digital tests.) The following
tests display the status of the analog inputs to the message
center indicator module. To sequence through the different A/D
tests, press the VEHICLE SETTINGS button to sequence forward,
and the TRIP ODO button to sequence backward. For the analog
inputs associated with each test, refer to the A/D Input Table
below.These tests can be used with the corresponding pinpoint
tests (not included here) to verify if the message center
indicator module is working properly when NGS Tester is not
available to monitor PIDs.
A/D INPUT TABLE:
ANALOG INPUT
VOLTAGE
TEST NUMBER TESTED
A/D0 (zero) Battery
A/D1 Spare (N/A)
A/D2 Fuel Level
A/D3 Oil Temperature
A/D4 Spare (N/A)
A/D5 Spare (N/A)
A/D6 Switch Bank #2
A/D7 Switch Bank #1
8. DIGITAL PORT TESTS. The folowing tests display the status
of each of the digital (descrete) inputs to the message center
indicator module. To sequence through the different Digital
Port tests, press the VEHICLE SETTINGS switch to sequence
forward, and the TRIP ODO switch to sequence backward. see
below for the digital inputs associated with each test. These
tests can be used with the corresponding pinpoint tests (not
included here) to verify if the message center indicator
module is working properly.
DIGITAL PORT TESTS
TEST # PORT FUNCTION TEST USED
PORT A Engineering (N/A) (N/A)
PORT B Engineering (N/A) (N/A)
PORT C Engineering (N/A) (N/A)
PORT D Engineering (N/A) (N/A)
PORT E Engineering (N/A) (N/A)
PORT F Digital Input Ports Digital Port
PORT G Engineering (N/A (N/A)
PORT H Engineering (N/A) (N/A)
PORT F BIT DEFINITION
PORT F BIT 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2
Bit Oil Washer Coolant Air Ride Air Ride Run
Function Level Fluid Level Switch Warning Detect
Level
BIT = 0 Oil Low Coolant Air Ride Air Ride Run
Level Washer Level Switch System Voltage
OK Fluid OK OFF OK ON
BIT = 1 Low Oil Washer Low Air Ride Check Run
Level Fluid Coolant Switch Air Voltage
OK Level ON Ride OFF
Switch
Message
Center
Indicator
Module
Pin # C208-23 C208-31 C208-29 C246-12 C208-22 C246-10
Wire W/PK PK/Y LB BR/PK DG/LG BK/PK
color
Bit 1 and Bit 0 are not used and have no input or Connector
Numbers.
9. DISPLAY DIMMING TEST. This test displays the status of the
dimming value sent to the message center indicator module over
the SCP (Standard Corporate Protocol) network by the steering
column/ignition/lighting (SCIL) module, as well as the
internal dimming level set by the message center indicator
module.
(1.) Press the VEHICLE SETTINGS button to increase the vacuum
fluorescent display (VFD) dimming level and the TRIP ODO
button to decrease the VFD dimming level.
(2.) NOTE: The SCP value displayed indicates the vehicle
dimming setting commanded by the SCIL module.
NOTE: When the SCP level changes, the message center indicator
module will immediately change the VFD dimming level to the
one that corresponds to the SCIL module commanded SCP level.
Note that the message center indicator module illumination
brightness will vary in response the the SCP/VFD brightness
level commanded.
Rotate the instrument panel lamp dimming control wheel.
These tests can be used with the pinpoint tests (not included
here) to verify if the message center indicator module is
working properly when NGS Tester is not available to monitor
PIDs and send commands.
The SCP or Standard Corporate Protocol is a system in Lincolns
(and other Ford manufactured models) that allows module to
module communications to keep the number of wires from going
all around the car. For instance the speed sensor is connected
to only one module (usually the speed control module) and that
information is shared with other modules through the SCP
system. In a '97 and '98 Mark VIII there are 10 modules that
use this system to send data all around the car. For example,
the passenger's door has only 1 switch in it for door ajar,
and inside lighting. The passenger's door uses the SCIL module
to monitor the switch, but the driver's door is monitored by
the driver's door module and the data is sent by the SCP to
the SCIL module that the driver's door is open or closed. The
speed sensor is also sent to the instrument panel via SCP
which operates the speedometer. It is also sent to the SCIL
module which will not allow the trunk to be opened by the
inside switch or key fob while the vehicle's speed is over 5
mph. All of these signals are sent through the SCP. I call it
a way of module to module communication that we (Ford) know
of, but you don't. An NGS tester is the only tester that will
read and simulate the SCP signaks. It will test out the
speedometer, the temperature guage, etc., without any other
outside source. I have called other OBDII tester manufacturers
and none of them can even read the information on the bus, let
alone generate the signals for it. It is probably not that
complex, but there is no information in the service manuals
explaining it at all.
You can use a small putty knife and get under the switch
assembly and pop it out of the mount without removing all the
things the manual says to. I have done it several times to my
car, but I would not do it in the winter as you need some
flexing of the plastic pins.
I hope you can get into the testing mode. If not, then you'll
need the NGS, which is something by itself can read and write
data into the message center.
