[phaco]

I've been having a somewhat intermittent hesitation problem ever since I took possession of my 2007 2.0T Combi a month and a half ago (5yr powertrain warranty expires April 3rd). Spent $300 so far on dealer diagnostic time only to be told (after the third visit) to come back when a CEL showed up as they don't have access to a Saab troubleshooting engineer anymore (because bankruptcy) to help them when TECH2 stays silent. For reference purposes, symptoms had been more evident when the engine was cold, hesitation was slight to moderate and most obvious from 1500 to 3500 rpm, pulled plugs were covered in carbon deposit (soot, got new plugs) and the month-old oil is already looking dark/almost black. I guess it's been running rich for awhile for whatever reason (please note I'm mechanically inept).

I thought I'd start by running fuel injector cleaner (had a four or five year-old bottle of Redline SI-1 which I dumped at my last fillup about a week ago), give it a bit of the Italian tuneup treatment, then perhaps Seafoam through a vaccum into the intake and hope for improvement (haven't got around to the Seafoam yet). Quite the opposite, seems to me the hesitation has become more apparent and is now more obvious higher in the rpm range (peak at about 3500-4000).

Check engine light came on yesterday (with what I think is Limp Home mode, ie. no power in first and second gears below about 30-40 km/h but normal above that), bought a $25 code reader (P1681), downloaded WIS for the verdict : No pulses generated to the control module input of throttle position sensor 2. Dealer service guy first told me over the phone it was Throttle Body Assembly and covered under powertrain (although backordered -- the sensors are not available independently), but then called back later after talking to one of the techs and they now think it's ECU (Trionic 8 Control Module) and not warrantied.

I know I should probably check the electrical connections between TB and ECU but we're in a snowstorm right now and I don't have a garage, so that will have to wait for a bit (besides I'm not really sure how to do that without getting fried or breaking anything). I'm writing all this to see if anybody has had this problem before or has any suggestions for me before I go plunking cash I don't have on a "perhaps fix" expensive ECM (couldn't find any 2007+ used ECU online, part #55565504). I'm starting to miss my T5 9-3... Any help is appreciated, thanks.

 

[Xeo01]

If you go through the diagnostics in the WIS it does say that your fault code requires the ECU to be replaced. Have you tried disconnecting your neg battery cable for 10min and seeing if just resetting the ECU that way fixes your issue?

 

[aerojon]

here's some previous threads/posts

get the injector seals checked also.

http://www.saabcentral.com/forums/showthread.php?t=149724&highlight=p1681

http://www.saabcentral.com/forums/showthread.php?t=132116&highlight=p1681

 

[phaco]

If you go through the diagnostics in the WIS it does say that your fault code requires the ECU to be replaced. Have you tried disconnecting your neg battery cable for 10min and seeing if just resetting the ECU that way fixes your issue?

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I have not as I've thought so far the problem was mechanical not electrical, will get to that tonight after work. Thanks.

 

[phaco]

here's some previous threads/posts

get the injector seals checked also.

http://www.saabcentral.com/forums/showthread.php?t=149724&highlight=p1681

http://www.saabcentral.com/forums/showthread.php?t=132116&highlight=p1681

Thanks for those links, bizzarely I hadn't caught the second one in my previous search. The conclusion in that thread was engine mounts solved the problems, that was a few years ago I sent a PM to the poster jackchoo to check on his status but I don't think he's been active here for a while. I'm not sure engine mounts could be the problem on mine, but his conlusion makes checking the connections even more pertinent I would think.

By the way my idle seems perfect, contrary to most other hesitation/stuttering threads I've found.

Does anyone know if I can unplug the ECM to check on the connectors or will that mess anything up (eg. need Tech II to get rolling again or something). Thanks

 

[micakaj123]

I had to replace the throttle body assembly on my 07, I had the throttle position sensor code as well (sports sedan).

The dealer raped me, it was like 150 to diagnose and like 650 for parts and labor. They replaced my pedal basically. Its held by like 2 screws. If I would have known I would have bought the part and did it myself. The computer in it was the problem. I was going into limp mode as well.

Conniving *******s

They piss me of with labor lol. Best to do things yourself. They charged me probably like 300 just to change the pedal. But if this helps you out then great, at least something good can come out of it lmao

 

[phaco]

I had to replace the throttle body assembly on my 07, I had the throttle position sensor code as well (sports sedan).

The dealer raped me, it was like 150 to diagnose and like 650 for parts and labor. They replaced my pedal basically. Its held by like 2 screws. If I would have known I would have bought the part and did it myself. The computer in it was the problem. I was going into limp mode as well.

Conniving *******s

They piss me of with labor lol. Best to do things yourself. They charged me probably like 300 just to change the pedal. But if this helps you out then great, at least something good can come out of it lmao

Thanks for the info, yours seems to be a different problem though. From what I've learned there are 2 Throttle Position Sensors on the throttle body itself (bolted to the intake manifold, which can only be changed by changing the whole TB assembly @ ~C$800 + labour, but covered under Powertrain Warranty), and then an Accelerator Pedal Position Sensor located (I assume) at the pedal (which is probably what was defective in your case, I've seen others with that problem researching mine). Do you remember the exact trouble code it was throwing?

 

[micakaj123]

No sorry I don't it was about a year ago. All I know is that he said we replaced the throttle body. He could have completely lied but there was no way for me to know lol.

 

[phaco]

No sorry I don't it was about a year ago. All I know is that he said we replaced the throttle body. He could have completely lied but there was no way for me to know lol.

Oh I misunderstood so they did change the whole TB. Glad at least that fixed it for you. I'm going through the dealer in the hope of getting this warrantied, either through Powertrain (TB) or Major Emissions Component (ECU).

 

[phaco]

New fault code tonight, on top of the still extant P1681: P2135 Throttle Position Sensor Circuit, Plausibility fault between Circuit 1 and 2.

To be more precise, the CEL had cleared by itself, then came back. I guess this would point back to the throttle body sensors or the connection between TB and T8 module, less likely the T8 module itself. Dealer is closed and I haven't had a chance to look under the engine cover yet. Weather-dependent I'll try to get a peek this weekend.

 

[aerojon]

http://www.saabcentral.com/forums/showthread.php?t=137152&highlight=P2135

 

[phaco]

Quick update: with the new code P2135 the dealer now thinks I need a Throttle Body Actuator unit, thankfully covered under the crumbs of GM 5-yr Powertrain Warranty I have left (and apparently not backordered any more). I'll chime back in next week once the TB is installed.

 

[dude_bro]

I didn't take the time to read everyone's replies but I had this same issue with my VW Gti, I had a built motor with a big turbo set up. We replaced the throttle body 3 time and it would be fine for a little while but the problem always returned. I began to insist it was the tune but was called crazy, in the end it wa related to the tune, the person who bought the car tuned it with a different company and hasn't had a problem since.

Not sure if that helps, but..... That my experience with the same codes, different vehicle.

 

[phaco]

I didn't take the time to read everyone's replies but I had this same issue with my VW Gti, I had a built motor with a big turbo set up. We replaced the throttle body 3 time and it would be fine for a little while but the problem always returned. I began to insist it was the tune but was called crazy, in the end it wa related to the tune, the person who bought the car tuned it with a different company and hasn't had a problem since.

Not sure if that helps, but..... That my experience with the same codes, different vehicle.

Thanks for your input. AFAIK I'm not tuned, although I am planning a VTune soon. Hope the replacement unit fixes this once and for all, my warranty expires in April...

 

[Xeo01]

Wish you luck!

 

[dzlsabe]

That P1681 does most likely mean an ECU, the second a throttle body, but I would disconnect the battery - and clean the throttle body...Ive seen a lot of TB codes go away after this is done.

 

[Piper of Rose]

I would recalibrate the throttle. This worked for me.

1)fullly depress the pedal with the car off.
2)Start the car with the pedal fully depressed.
3)after the car has fully started let off the pedal.

number 2 recals the throttle to 100% number 3 recals the pedal to 0%. This is not confirmed with SAAB but it worked for me.

 

[phaco]

My dealer only received the Throttle Body last week, took 3 weeks for the part to come in from the States (apparently got stuck at the border). My second daughter was born last Monday so my trip to the dealer had to wait until today.

Verdict:

- idle seems smoother (wasn't exactly rough to start with, very smooth now),
- pickup from standstill is much improved (seemed a little sluggish before compared to other 2.0T's I had driven) and better throughout the rev range,
- no more hesitation! In short the car feels transformed, so smooth.

Lots of hard acceleration and woohooing on the short trip back from the dealer!

When I asked the tech what the old TB looked like he said it was pretty dirty and that the plate couldn't close completely. I assume it was fouled with the same carbon deposits present on the old spark plugs and around the tailpipe.

Not sure if this is cause or consequence (ie. if the fouling will now start again on the new part), what could cause rich running other than frequent low speed stop and go and perhaps bad gas (these are what the service manager told me were the likely culprits)?


Oh forgot the best part: total cost for this trip was $0 as this is covered under the GM 5 year 160,000km Powertrain Warranty.

 

[phaco]

I would recalibrate the throttle. This worked for me.

1)fullly depress the pedal with the car off.
2)Start the car with the pedal fully depressed.
3)after the car has fully started let off the pedal.

number 2 recals the throttle to 100% number 3 recals the pedal to 0%. This is not confirmed with SAAB but it worked for me.

New TB had solved my probelm until yesterday, got a related code but neither of the two that originally appeared. Just got P2138, read your thread on 2135, followed your steps and went for a drive. So far so good, fingers crossed. Thanks for your help BTW.

 

[DjPopeyeSaab93]

so what was the fix they did?