Mitsubishi 3000GT Service Manual page 860

SERVICE BRAKES - Anti-lock Braking System Troubleshooting
B ABS warning light stays on when the ignition key is in the "ON" position.
[Explanation]
This is the symptom when the ABS ECU does not
power up due to broken ECU power circuit, etc.,
when the fail safe function operates and isolates
the system or when the warning light drive circuit
is short circuited.
RELAY
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10
[Hint]
Check the on-board diagnostic output and if there
is no output voltage or if the scan tool and ABS
ECU cannot communicate, there is a good possibil-
that power is not flowing to the ECU.
Caution
l
Is there diagnosis output?
(Is there communication with
scan tool?)
Yes
I
Does diagnostic trouble code
output display normal codes? iNo
Yes
Does the ABS warning light re-
main illuminated even with the
ECU connector disconnected?
Yes
Does the ABS warning light re- -
main illuminated even with the
HU connector disconnected?
Yes
or ECU and ABS warning light
25
TSB Revision
If the diagnostic trouble code is output, the
system can be in the fail safe mode. In such
a case, erase the diagnostic trouble code
and then restart the engine to check if the
system is currently in a fault condition.
No
Replace ECU.