87 xj
4.0
I have the fsm.. description is too general and wiring diagram is useless.. i dont get it
I thought the b+ latch relay works with the IAC.. but the
wiring diagram shows me theres no terminal connected directy to rhe IAC.
4 pins
1 to 12v from battery when you switch on
2 to the feed of the relay coil and ecu
3 to the ground of the coil and ecuador
4 to the pin 2
i know the iac could be moved by the ecu not the b latch
but how the hell is feed it self

Description says . Whe. You shut off rhe engine the b latch relay stays or maintain the system or engine active for 1 sec for smooth shut off and also for the next start
.the auto feed is confusing me.. i can upload a pic of the diagram to explain me better

 

The ECU stays live for a short period after shut off to feed the IAC so it goes back to idle/new start position for an easier start.

 

The B+ Latch relay keeps your ECU powered after you turn the key off.

This allows the engine to shut down smoothly.

Without it, the IAC valve would snap shut instantly. The engine would jerk and lurch to a stop.

The relay provides power for one second so the ECU can retract the IAC valve slowly.

This creates a calm, normal engine shutdown.

 

That sounds fair. But what about the loop?
what part times the ecu to be powered?
The relay itself?
Or the ecu itself
.that loop or feeditself is making me think the ecu feed and ground . Also im restoring my XJ now and the IAC is disconnected ( visual inspection = closed permanently)