ABS on 740 -89 engages before standstill

[viktor weisshaeupl]

The car is a 1989 740 TDI station wagon. Since a few weeks I feel that the
ABS engages also on dry surface during the very last time just before
standstill on dry surface. It does not interfere with braking at all. I
haven´t touched anything yet. My Haynes manual is not helpful with this
problem. Any idea what I could do myself for diagnosis? Any website with
info on troubleshooting?

 

[radietz]

The car is a 1989 740 TDI station wagon. Since a few weeks I feel that the
ABS engages also on dry surface during the very last time just before
standstill on dry surface. It does not interfere with braking at all. I
haven=3Ft touched anything yet. My Haynes manual is not helpful with this
problem. Any idea what I could do myself for diagnosis? Any website with
info on troubleshooting?

This is usually caused by excessive resistance in one or both connectors
for the the front wheel sensors. Volvo provides wire harness connector
pigtails that can be soldered in to replace the harness side of the
connector. It's possible that the rear sensor wires were damaged during
manufacture and have corroded inside the insulation to the point where
there are only one or two strands of conducting wire left. Change all
six wire ends and the problem should go away.

Bob

 

[viktor weisshaeupl]

This is usually caused by excessive resistance in one or both connectors
for the the front wheel sensors. Volvo provides wire harness connector
pigtails that can be soldered in to replace the harness side of the
connector. It's possible that the rear sensor wires were damaged during
manufacture and have corroded inside the insulation to the point where
there are only one or two strands of conducting wire left. Change all
six wire ends and the problem should go away.

Thank You for the hint. You are talking of six wire ends ? 2 on the each
front wheel and 2 on the wire to the back axle?

Viktor, Vienna, Austria