My truck ABS does not do it.
The FSM says the system runs the pump briefly and activates the solenoids after the ignition is turned ON. I have never heard the pump on, even briefly, other than during an actual ABS braking event. It is hard to miss the growl of the ABS pump.
I installed a scope at the ABS system fuse to monitor the current draw. With the Tech2 I can activate the pump and the solenoids and see the corresponding current draw on the scope. However, turning the ignition on and even starting the engine, the only current draw is the system relay being turned on. The pump and the solenoids are never activated.
Does anybody actually hear the ABS pump being tested at ignition ON?
The FSM says the system runs the pump briefly and activates the solenoids after the ignition is turned ON. I have never heard the pump on, even briefly, other than during an actual ABS braking event. It is hard to miss the growl of the ABS pump.
I installed a scope at the ABS system fuse to monitor the current draw. With the Tech2 I can activate the pump and the solenoids and see the corresponding current draw on the scope. However, turning the ignition on and even starting the engine, the only current draw is the system relay being turned on. The pump and the solenoids are never activated.
Does anybody actually hear the ABS pump being tested at ignition ON?