Anyone Familiar With The Saab Throttle Body Problem ?

A 2000 9 3 turbo. Has code P1260.

I have looked around and found that this means that the PWM going to the throttle control is too small. There is a reset procedure which has been done but didn't fix it.

Must be current detected because from what I've read it will throw the same code if the wiring is bad to the umm, thing. I believe it must be a solenoid that works against something to open the throttle to increse idle.

I find it hard to believe it is a wiring fault because it is not going under the car. The harness does not appear to be dmaaged in any way. Wires in a harness lke that don't just break, and if they did and that's the problem, why always those wires ? Makes no sense.

Got a couple of weeks to iron this out before the emissions testing. Been looking for the full manual. I did find some testign procedures online but they seem to require a special tool from Saab. This car is a little too old for that, so I am looking for ways to figure this out without it. I found the ECU, and now have to figure out how to unplug it. Online there was a diagram showing which connections at the plug go there, and I don't esapecially want to break anything.

Actually I am considering seeing if I can take the cover off the ECU and check continuity from the board itself. In fac might find some bad solder connections - now this has not been specifically tested but I thnk the next is a load test. It is a stick so I could just leave it at idle and start letting out the clutch and see what is on that circuit.

Any ideas ? TIA

 

I am familiar with the interactions, like the MAP or MAF (a few have both) and the O2 (or lambda) sensor. Those are almost always wrong, really if it says it is too lean you can almost count on it being too rich.

However this code is peculiar to engines with an electronic throttle it appears. this one is tubocharged and it probably provides for a rev limiter.

When it detects not enough output to the throttle solenoid I guess, it assumes the spring is weak. I am not sure on what this is based. Either it is detected engine output versus expected, or it is somehow compared with the mechanical throttle position.

One thing though, of all the stuff I have seen on the internet, a bunch of it mentions cleaning the throttle plate, which some people insist on calling a butterfly. I can see in such a system where the thing hanging up could cause this problem.

Anyway, I am going to have another look at it later today and see what I can find. you might be right about the throttle body but the way this acts I tthink it may have/had a tendency to stick shut. I am sure the force to the throttl plate is limited and this is what happens I guess.

There is alot of talk about resetting it from the limp home mode. Apparently when it detects less than a certain duty cycle going to the coil it takes and slams the solenoid all the way for a second which then disengages the electronic throttle and uses the regular mechanical throttle.

I was going to actually throw a scope on the wires to that thing but first I have to get the ECU out of limp home mode. It is not going to drive that throttle elctronically when it itself is in limp home mode. Resettting it involves a screwdriver and turning a geas tha tis right under the mechanical throttle linkage.

That's why I posted, someone might know that I need a $15 gear or something, or as you mentioned, just clean the thing.

I want a 1967 Chevy, really.

 

[Gareth Magennis]

wrote in message
news:65cab0c3-588a-402b-8026-1288a766637a@googlegroups.com...

A 2000 9 3 turbo. Has code P1260.

I have looked around and found that this means that the PWM going to the
throttle control is too small. There is a reset procedure which has been
done but didn't fix it.

Must be current detected because from what I've read it will throw the same
code if the wiring is bad to the umm, thing. I believe it must be a solenoid
that works against something to open the throttle to increse idle.

I find it hard to believe it is a wiring fault because it is not going under
the car. The harness does not appear to be dmaaged in any way. Wires in a
harness lke that don't just break, and if they did and that's the problem,
why always those wires ? Makes no sense.

Got a couple of weeks to iron this out before the emissions testing. Been
looking for the full manual. I did find some testign procedures online but
they seem to require a special tool from Saab. This car is a little too old
for that, so I am looking for ways to figure this out without it. I found
the ECU, and now have to figure out how to unplug it. Online there was a
diagram showing which connections at the plug go there, and I don't
esapecially want to break anything.

Actually I am considering seeing if I can take the cover off the ECU and
check continuity from the board itself. In fac might find some bad solder
connections - now this has not been specifically tested but I thnk the next
is a load test. It is a stick so I could just leave it at idle and start
letting out the clutch and see what is on that circuit.

Any ideas ? TIA




One idea, don't even think about blaming the ECU until you have established
this is likely the problem.

Also, the codes generated by the ECU often point to completely the wrong
thing.

For example, suppose you have an air leak between the MAF and the inlet
manifold.
The ECU reads from the MAF that x amount of air is entering the engine, but
because of the leak, a lot more actually is.
The ECU then injects x amount of fuel.
The ECU then reads the Oxygen sensor in the exhaust to discover this reading
says the mixture is weak, so it injects more fuel.
This doesn't work and the various readings just don't tally with one
another.

So the ECU throws up an error code. Could be MAF sensor faulty. Could also
be Oxygen Sensor faulty. Could also be an injector problem.
Who knows what the ECU is gonna tell you cos it doesn't actually know.

Turns out the problem is an air leak, which the ECU will never suss out.



In your case it might simply be a dirty throttle body, dirty ISCV, dirt or
grunge holding the throttles butterfly valve slightly open at idle, etc etc.
Try cleaning stuff and looking for air leaks before thinking a faulty ECU.



Remember Occam's razor?





Gareth.

 

jurb6006@gmail.com wrote:

One thing though, of all the stuff I have seen on the internet, a
bunch of it mentions cleaning the throttle plate, which some people
insist on calling a butterfly.

I used to drive a '90 Ford Tempo with a 4-cylinder 2.2 liter engine.
Every so often, it would start doing two things: 1) idling a little
rough and 2) if you just barely cracked the throttle open slowly, it
would stumble a little and then come up to speed. (If you stomped on
the pedal to bring up the RPMs quickly, it ran fine.) It was only OBD-I,
and it wouldn't throw a Check Engine light or codes for this.

It had a mechanical throttle linkage, plus an idle air valve that used
a solenoid to leak a controlled amount of air around the throttle plate.

What fixed 1) was to take the idle air valve off and clean the working
end of it with some carb cleaner, rags, and something to poke the rags
into the housing. (It had a cast housing with the air ports, and a
pointy metal valve that was connected to the solenoid. Very much like
the working end of an EGR valve.)

What fixed 2) was taking off the rubber hose from the air filter box,
opening the throttle all the way, jamming a plastic screwdriver handle
in one half of the opening to hold the throttle open, and using a rag
and some carb cleaner to get rid of the ring of gunk that had
accumulated just under the throttle plate (on the engine side). Then
move the screwdriver to the clean half and do the other half. The
gunk didn't really make the throttle plate stick closed (as far as I
could tell); it just blocked a tiny amount of the air flow when the
throttle was just barely open.

I usually ended up doing both of the above about once a year, which
was about every 10k-12k miles. That'd clear it up for another year or
so. This was when the car had 70,000+ miles and 12+ years on it.

I can see in such a system where the thing hanging up could cause this
problem.

On the wayback machine, on some cars, eventually the steel shaft for the
throttle plate would wear down the light alloy carb body, causing the
shaft to flop around, and the carb to suck air around the shaft. It
could be temporarily fixed with lots of RTV on the carb body. The
permanent fix was to take it to the carb shop, where they would take out
the throttle plate and the shaft, drill the holes in the body oversize,
press in some brass/bronze bushings, and then reinstall the shaft and
plate. I had this done to the carb for my old VW and it improved the
situation greatly. If this car has a ton of miles, maybe something like
that would help.

If there's still a mechanical cable from the pedal to the throttle, make
sure it's not hanging up, or coming out of its fastenings, or something.
(Are the motor mounts in good shape? Sometimes things get in a jam if
the engine moves around.)

That Ford had a cable from the pedal to the throttle, and then a linkage
with rods and ball-and-socket joints from the throttle to the kickdown
lever on the automatic trans. The plastic clip for one of the ball-and-
socket joints broke one day, so that car lived out the rest of its days
with some baling wire wrapped around the joint to hold it together.

The other thing I would try is to unplug and replug the connector(s) to
the throttle positioner / throttle position sensor under the hood. Also
look for evidence of crap in both halves of the connector, cracked
connectors, etc. If you have some real thin shim stock and can cut it
to match the male pins, you might try plugging a piece of shim into the
female sockets, just to see if one of them has lost its spring tension.
If you don't have thin enough and narrow enough stuff, don't do this...
it'll screw up the female sockets.

A lot of times the power supply to all the sensors and actuators comes
from the ECU, but if it comes straight from +12 V, maybe R&R the fuse
and/or relay it comes through... sometimes the terminals get crudded
up.

> There is alot of talk about resetting it from the limp home mode.

I did probably the same Google searches you did. This thread
http://www.saabscene.com/forum/threads/111235-management-warning-code-p1260
says to pull fuse 17 (ECU) for 5 minutes to clear the trouble codes in
the ECU.

Matt Roberds

 

We just got more.

y neighbor has the code reader. Talking to him, I am pretty sure he is a pro at this, or a fucking damgood amateur. Whatever it is, when we reset the throttle body mechanically, it appears the reason the check engine light stayed is becauser of a code likely generated by the O2 or lambda sensor.

My neighbor read the actual values out the O2 sensors n shit. His evaluation is not so much to clean the main bore in the throttle body, but to take it off and apart, and clean everything. I think he is talking about EGR ports myself but I could be wrong. He said there are "air" ports down there and they get clogged, partially clogged and all that shit.

Anyway, he saw the first O2 sensor fluctuating all over the place and said that is probably bad, but more likely there are leaks at the throttle body.

We are definitely proceeding in that direction. Coupkle of gaaskets and some carb cleaner type shit, yeah, that sounds good.

It either woprks or it doesn't. Tomorrow is Sunday, and people got shit to do, but in the next few days we'll probably do this. See what happens.

In faxct if it rains too much and we can't do it, if that cheeck engine light does not come on it is going to the EPA station immediately, but they are no topen until Monday.

This thing is not pollutiong the air at all. This is a matter of revenue or something. This fault makes the idle speed just a bit low, 400 RPM.

Shit, that is burning LESS gas !

Goddamn rentseekers and revenuers !

Whatever, but don't get the idea I think people should be able to drive smoke machines all over the place. Not at all. My cars always run right.

anyway, I guess I'll keep you posted.

 

jurb6006@gmail.com wrote:

Anyway, he saw the first O2 sensor fluctuating all over the place and
said that is probably bad, but more likely there are leaks at the
throttle body.

The first O2 sensor (between the engine and the catalyst) is *supposed*
to fluctuate. If you plot the voltage vs time when everything is
working right, it looks like a sine wave with a period of a couple of
Hz. If it's a flat line, the O2 sensor is probably bad. If it's a
funky-looking wave, either the O2 sensor is trying to crap out, or it's
accurately telling you that the engine is doing something weird.

The *second* O2 sensor (after the catalyst) should have a relatively
smooth output. If it has a sine wave, just like the first O2 sensor,
then usually the catalyst isn't doing its job.

In faxct if it rains too much and we can't do it, if that cheeck
engine light does not come on it is going to the EPA station
immediately, but they are no topen until Monday.

Gee, Rocky, that trick never works!

There are several things that an OBD-II computer checks on. Things like
misfire it can check any time the engine is running. It can only check
the catalytic converter after the engine has been running for a while
and heated it up. It can only check some of the components (like EGR)
when you've been driving at a certain speed and load for a little while.

It keeps track of which tests have and have not run, and that's visible
when the smog test place plugs in the scan tool. On my old PC-based
scan tool, on a 2001 Toyota, there are 7 tests listed: misfire, fuel
system, component, catalyst, evaporative system, O2 sensor, and O2
sensor heater. If I clear the codes and start the engine, cold, the
first three will show as "tests have run" within a few seconds, but I
have to actually drive the car to get the other four to show that the
tests have run.

I know in California if not all the tests have run, the smog test
station will tell you to go drive it up and down the freeway a few miles
and come back. I don't know if that's the case where you live.

> This thing is not pollutiong the air at all.

If the engine's running, it is. The goal is to minimize it as much as
economically possible.

> Shit, that is burning LESS gas !

Tuning for best fuel economy is actually a little different than tuning
for lowest emissions.

Matt Roberds

 

Thanks for the info.

"Tuning for best fuel economy is actually a little different than tuning
for lowest emissions. "

Actually if not for the catalytic it might be. But that is all on the other end.

Check engone came back on within a day. Don't know which code it is yet. We figure if the throttle body is in lip hoe mode then that's that, if not it should be the 1252.

I probably won't see the car agian for a couple of days. When I do I'll keep you "posted".

 

[M Philbrook]

In article <65cab0c3-588a-402b-8026-1288a766637a@googlegroups.com>,
jurb6006@gmail.com says...

A 2000 9 3 turbo. Has code P1260.

I have looked around and found that this means that the PWM going to the throttle control is too small. There is a reset procedure which has been done but didn't fix it.

Must be current detected because from what I've read it will throw the same code if the wiring is bad to the umm, thing. I believe it must be a solenoid that works against something to open the throttle to increse idle.

I find it hard to believe it is a wiring fault because it is not going under the car. The harness does not appear to be dmaaged in any way. Wires in a harness lke that don't just break, and if they did and that's the problem, why always those wires ? Makes no sense.

Got a couple of weeks to iron this out before the emissions testing. Been looking for the full manual. I did find some testign procedures online but they seem to require a special tool from Saab. This car is a little too old for that, so I am looking for ways to figure this out without it. I found the ECU, and now have to figure out how to unplug it. Online there was a diagram showing which connections at the plug go there, and I don't esapecially want to break
anything.

Actually I am considering seeing if I can take the cover off the ECU and check continuity from the board itself. In fac might find some bad solder connections - now this has not been specifically tested but I thnk the next is a load test. It is a stick so I could just leave it at idle and start letting out the clutch and see what is on that circuit.

Any ideas ? TIA

TPS (Throttle Position sensor)?

I beleve with some cars it'll go into limp mode and use other sensors
to detect the average intake of air and attempt to create an aproximate
throttle position. A bad feed back sensor (TPS) may report your throttle
at being to low of a position. This cuts idle back a bit and makes the
pulses to the throttle body injectors kind of narrow...

Also cam and lower flywheel sensors can put it in limp mode if they
don't both agree. Loose belt, bad sensor etc..

Of course, vacuum leaks around the carb area and intake could also
through a monkey into it!

Jamie