Volvo TSI, Manual, Page: 202 / 250

Group 28 Troubleshooting
MID 144 PID 84 Road Speed
The speed signal comes from a sensor on the transmission or as a digital signal if an
electronically-controlled transmission is used (i.e. Allison). Diagnostic settings (level 1.5
parameters) are factory programmed based on the transmission type used.
•
Text Messages
In vehicles equipped with diagnostic display, the fol-
lowing message(s) will appear:
•
Instrument Cluster Graphics Display (VN):
Road speed.
•
Data Link Instrument Cluster (WG, AC, WX):
The Data Link instrument cluster graphics display
used on WG-, AC-, and WX-series vehicles can
display a limited number of text messages. For infor-
mation, see “Data Link Instrumentation,” Volvo
Service Publication PV776–381–620SM.
•
VCADS Pro Display:
Road speed
Fault Codes
FMI 5
Abnormally low current or open circuit.
Conditions for fault code:
•
If the VECU registers a current lower than 90 A on
any of the signal wires from the speed sensor the
VECU interprets this as a fault and an fault code is
set.
Possible cause:
•
Poor contact, sensor connection.
•
Switch resistance and oxidation.
•
Break, signal wire.
•
Fault in sensor.
Reaction from the VECU:
•
Yellow lamp lights up.
Noticeable external symptom:
•
No vehicle speed on gauge.
•
No PTO.
•
No cruise control.
FMI 6
Abnormally high current or short circuit.
Conditions for fault code:
•
If the VECU registers a current higher than 140 A
on any of the signal wires from the speed sensor,
the VECU interprets this as a fault and an fault code
is set.
Possible cause:
•
Signal wire short-circuited to higher voltage.
•
Signal wire short-circuited to ground.
•
Fault in sensor.
Reaction from the VECU:
•
Yellow lamp lights up.
Noticeable external symptom:
•
No vehicle speed on gauge.
•
No PTO.
•
No cruise control.
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