Solenoid Valve Relay 3019A - Volvo ECS Training Tips And Tactics

ECS Gen. 1
When the ignition is switched on, a ʻsensingʼ signal of 2
Solenoid valve milli-volts is sent from ECU pin (29) through each individual
solenoid and back to the ECU.
relay 3019A
This signal checks to ensure that the solenoid circuits are
OK.
If the return signal to pins 3, 4, 5, 6, 7, 8 and 9 is not
correct, relay 3019A will not be energised.
If the return signal is correct, ECU pin 10 will supply a
negative to relay pin (85).
Because ECU pin (15) supplies battery voltage to relay pin
(30) and - by link - to pin (86), the relay is now energised
and supplies battery voltage to the solenoids via pin (87).
ECU pins 3, 4, 5, 6, 7, 8 and 9 also supply battery voltage
to the solenoids so, the solenoids are not energised.
To energise a solenoid, the ECU changes the supply from
the relevant pins from battery voltage to negative.
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