[godwinaustin]

Hi everyone, the 1995 Aero (manual) I just bought had the ABS relay pulled by the previous owner when he had ABS issues and couldn't figure out a fix. I dont need or want ABS, or certainly not enough to fix it.

is it true that no ABS relay / ABS system fault will keep me in base boost? (the boost gauge is also not working, so I can't see boost levels)

If the APC will limit boost with an ABS fault, Is there a way to mod the APC system to ignore the fault and provide full boost?

 

[davide c]

New one on me.
I've had an abs issue (intermittent warning light) for over 12 years.
It has Zero effect on Boost. Or curiously on abs function either.
I long ago gave up on trying to fix it.
Unless yours is a TCS equipped car .. those are Very odd setups.. I'd look for the standard low/no boost causes.
Check / reconnect the wee boost hose to your dash gauge.. it's useful.

 

[Banman]

Hi everyone, the 1995 Aero (manual) I just bought had the ABS relay pulled by the previous owner when he had ABS issues and couldn't figure out a fix. I dont need or want ABS, or certainly not enough to fix it.

is it true that no ABS relay / ABS system fault will keep me in base boost? (the boost gauge is also not working, so I can't see boost levels)

If the APC will limit boost with an ABS fault, Is there a way to mod the APC system to ignore the fault and provide full boost?

My ABS light is almost always on (F/L sensor wire to ground) my boost is fine.

1) why doesn't your boost gauge work?
2) you don't have an APC on a '95 9K -- you left that trash behind with T5.5 -- the one ecu controls fuel, timing, and boost -- trionic magic
3) check/replace all your vacuum lines & check the hoses from the inter-cooler to the throttle body.

 

[godwinaustin]

My ABS light is almost always on (F/L sensor wire to ground) my boost is fine.

1) why doesn't your boost gauge work?
2) you don't have an APC on a '95 9K -- you left that trash behind with T5.5 -- the one ecu controls fuel, timing, and boost -- trionic magic
3) check/replace all your vacuum lines & check the hoses from the inter-cooler to the throttle body.

Hey Banman, I fixed the gauge, it was a bad vac line, which I had suspected. As far as vac lines and charge hoses, the car boosts to the red with the wastegate unplugged from the BPC solenoid, so doesnt that mean I am not venting boost pressure due to a loose hose?

 

[godwinaustin]

And should add , I am boosting to halfway up the yellow on the boost gauge. If I remove the wastegate from the BPC, I hit the red.

 

[Banman]

Use google to search the tech forum.

There's a couple electrical tests to verify the boost control valve mounted to the radiator is working right. Sometimes you can clean 'em with solvent and they resume proper function...

Make sure your base boost/wastegate are adjusted right.
info starter kit...
http://jope.fi/saab/www.quasimotors.com/repairs.htm

https://www.thesaabsite.com/faqs/9000/FAQs.html#linkbar

I'm afraid this 9K forum is 'bout dead...

 

[chengny]

Hey Banman, I fixed the gauge, it was a bad vac line, which I had suspected. As far as vac lines and charge hoses, the car boosts to the red with the wastegate unplugged from the BPC solenoid, so doesnt that mean I am not venting boost pressure due to a loose hose?

You're doing the diagnostic correctly so far.

The first step is to isolate the problem - is it control/BPC valve related or a basic engine/turbo fault.

Due to the fact that full boost pressure was observed when you pulled the W hose from the BPC, a turbo/engine fault can be eliminated. That leaves just the control circuitry - or the BPC valve itself - as possible causes.

Next step is to check fuse 5 in the fuse block under the RH side of the dash. But I'm sure you did that. That fuse only serves two circuits - the APC system and the coolant circulating pump (only used with V6 engines).

A thorough inspection of the 3 hoses is next. Again, I'm sure you have done that.

Get your meter out and check the power supply:

Ignition switch in ON position.
Check that the valve is supplied with power (+54 circuit) by connecting one side of a test lamp/meter to pin 2 (the middle one) of the valve's connector and the other side to a good grounding point.

If you observe 12 volts at pin 2, that proves there is power available to the valve.

Check the resistance of the valve windings:

Take resistance readings in the valve's connector across:
Pins 1 and 2
Pins 2 and 3
Nominal resistance is 3 ±1 ohm in both cases.



Finally, check the lead connected to pin 3 of the valve:

Ignition switch in ON position.
Plug in the valve's connector. A weak buzzing sound should be heard.
If a sound can be heard, eliminate that part of the control circuit.


Unfortunately, that's about as far as you can go without an ISAT. I have had some success freeing up a sticking BPC with PBlaster. Just spray some into the 3 nipples, let it sit for a couple of days and hope for the best.

 

[davide c]

IF ? your Boost valve Meters as having Intact Coils.
The unit ..can.. be disassembled and rebuilt.
Razor saw it open on the glue lines..
fix/replace the disc valve and or the brass valve seats, the damage will be obvious..
then reassemble and use.
I've done 2 of these and they are still 'fine' after 6 yrs use.

Good luck