95 Q45 Active Controller

[franknitty69]

will an active controller from a 91Qa, P/N is 52700-64U00 work in a 95 q45a?

thanks

[3Q Jay]

yes. it won't have the same firmware optimisation.

what happened to the '95 control unit?

[franknitty69]

don't know what happened to the active controller. one day the active wasn't responsive (height didn't change upon starting). i checked the codes with the height switch, but it wasn't giving any.

i haven't actually tested the unit, but after reading the entire fa section of the fsm, i believe that the controller is bad due to the active system not being able to go into diagnostic mode and the entire active system is completely off.

[3Q Jay]

so you have a solid ACTSUS lite, and you can't get a self-diagnostic code by rocking the switch??

[franknitty69]

yep, active light is on and the active is fully disabled. won't go into diagnostic mode by turning the height switch.

i have already disconnected the battery for over 24 hours.

[3Q Jay]

does it go off even for a few seconds at engine start before coming back on?

What is measured battery voltage engine idling with full electrical load?

[Aussie Q45a]

does it go off even for a few seconds at engine start before coming back on?

What is measured battery voltage engine idling with full electrical load?

Is there a reason you ask the first question?The reason I ask is that is what mine does!!!

[3Q Jay]

yes, because if it stays on even after power-on initialisation, then there is a likely active ECU fault, or the battery voltage might be whack.

if it goes off it passes the reset that comes with every start cycle, if comes back on again, then it is a discrete fault--hopefully accompanyed by a code other than 55.

[franknitty69]

does it go off even for a few seconds at engine start before coming back on?

What is measured battery voltage engine idling with full electrical load?

key on, the light stays on, when the vehicle is cranked the light remains on. when the vehicle is started, the light is still lit.

i'm measuring 14.4 with radio on, defroster on, both heated seats on, ac/heater going.

[3Q Jay]

for completeness, check the battery voltage when you turn the key off.also, for troubleshooting, read it decay for the first 5 minutes after shutdown. at about 2-3 minutes after shutdown, the multivalve lets down, de-energising a solenoid, and the batt voltage should go back up a tad and stabilise.

for grins and giggles, put battery on trickle charge overnight, and start up fresh from a >13.2V baseline.

i'm starting to lean in your direction of suspecting the controller, might also try cleaning and re-seating the connector.

[lino]

yes. it won't have the same firmware optimisation.

Can you please explain the difference?

Thank you.