Released 5-1-08- Brake update on Redlines/GXP

[krisis7]

This is the most recent publication from GM-Release dated 5-1-08, still no hard part replacement.

05/01/2008 GM Training Magazine - SPRING EDITION
05/01/2008 Pedal Noise/Buzz, Extra Effort Needed to Depress Brake Pedal After Vehicles Has Not Been Driven for Extended Period Revised
05/01/2008 Bulletin GMP08-076 - GM Vehicle Care R134a Refrigerant (Part Number 12356150)


SERVICE - PONTIAC DEALERS / SATURN RETAILERS


Subject: Pedal Noise/Buzz, Extra Effort Needed to Depress Brake Pedal After Vehicles Has Not Been Driven for Extended Period Revised
Message #: VSS20081471-01

Corporate Bulletin Number 07-05-25-007A is currently available in SI.

Pedal Noise/Buzz, Extra Effort Needed to Depress Brake Pedal After Vehicle Has Not Been Driven for Extended Period of Time (Reprogram EBCM and ECM)
Models: 2008 Pontiac Solstice GXP
2008 Saturn SKY Redline
2008 Daewoo G2X

Attention: This bulletin will be released in two versions. The first release will be for vehicles equipped with an automatic transmission and built prior to the VIN breakpoints listed below. The second version of this bulletin will be released in May 2008 and will include all vehicles equipped with a manual transmission.
__________________________________________________ __________________________
This bulletin is being revised to provide system description and an updated correction. Please discard Corporate Bulletin Number 07-05-25-007 (Section 05 — Brakes).
__________________________________________________ _________________________


Model VIN Breakpoint
Saturn 8Y129355
Pontiac 8Y129363
Daewoo All Vehicles

Please make a copy of this bulletin and give it to your customer for future reference.

System Description
The 2008 Pontiac Solstice GXP, Saturn SKY Redline, and Daewoo G2X are performance vehicles that come equipped with the 2.0L (RPO LNF) engine and an advanced performance braking system called Optimized Hydraulic Boost (OHB). The OHB brake system utilizes the Anti-Lock Brake System (ABS) to assist vehicle braking in low brake vacuum conditions.

The brake systems on these vehicles use engine vacuum to assist the power brake system during most brake applications. The OHB system supplements the power assist brake system when there is low engine vacuum, such as when the engine is initially started after an extended period of no operation or while operating in high altitude.

Condition
Some customers may comment on one or more of the following brake system characteristics:
• Increased brake pedal effort due to low brake booster vacuum conditions that may occur after the vehicle has not been operated for an extended period of time and/or at higher altitudes and restarted.
• Brake pedal movement or pulsation accompanied by a ratchet sound coming from the brake system during OHB activation when braking.

Correction
Reprogram the ECM with an updated engine calibration. This new service calibration will increase engine vacuum when the vehicle is initially started.

Reprogram the EBCM with an updated brake calibration. This programming event will return the module to its original state if it was previously updated for this condition.

These calibrations will be available as an EBCM/ECM programming sequence event. From the controller list, select "EBCM/ECM Sequential Program."

Important:
• Allowing the engine to idle for a period of time after the engine is started will help increase the vacuum for the power assist brake system.
• Somewhat increased brake pedal effort and/or pulsation may still be experienced during cold engine start and braking with this revised calibration.
• If the SVC BRAKE SYSTEM message is displayed on the DIC. The brake system must be inspected for any faults in the system.

Refer to the Owner Manual (page 4-4 for the Pontiac Solstice or Saturn SKY) for additional information on this brake system operation.

[Bogie]

Originally Posted by krisis7

Reprogram the ECM with an updated engine calibration. This new service calibration will increase engine vacuum when the vehicle is initially started.

If anyone is getting this update, before you go, check the cold start RPM jump on initial start up before the fix, the warm up idle RPM, and the final idle. Then report the same values after the fix.

[shabby]

Didnt someone get a retro fit of the 07 parts recently? Why would they still be reprogramming the ebcm?

[Bogie]

Originally Posted by shabby

Didnt someone get a retro fit of the 07 parts recently? Why would they still be reprogramming the ebcm?

There was an original TB that changed the EBCM. If you had the EBCM change, the new TB requires it be reset to factory settings to work with the new ECM update.

Now here's the question in my mind. I wonder where jodenssky's SKY fits in the equation. Seeing as she has a retro vacuum pump, there is no need for this upgrade on her vehicle....but there is nothing in the current TB that acknowledges the possibility of having a vehicle so equipped.

Although jodenssky is the only one I'm aware of that has a retro vacuum pump, it must be accounted for in the corporate equation, because if the car ever goes in for service at a later date the TB must factor in the EBCM change required for the vacuum pump. If not, and they flash the EBCM under the current TB, it will no longer be calibrated to work with the vacuum pump.

Hmmm?

[vschaos]

very interesting! When the time comes I will be ordering me an 09

[mbeardsley]

This is definately encouraging though...sounds like they are at least working on the problem.

And maybe for those of us who only have a "slight" problem (not the major issues a few of us have reported), this could be good enough.

[Bogie]

Originally Posted by vschaos

very interesting! When the time comes I will be ordering me an 09

If they think this fixes the problem, all an 09 might get you is one less trip to the Service Dept 'cause the ECM and EBCM will be performed at the factory. They might not have an aux vacuum pump on the 09.

Originally Posted by mbeardsley

And maybe for those of us who only have a "slight" problem (not the major issues a few of us have reported), this could be good enough.

Yeah, instead of waiting 30 seconds, I can now be on my way in 15.

[TINOONIT]

where did you hear of this bulletin????

has anyone gotten anything in the mail about this yet???

[krisis7]

Originally Posted by TINOONIT

where did you hear of this bulletin????

has anyone gotten anything in the mail about this yet???

There will be no mailing, it was released to the Dealers in Dealerworld on 5-1-08 as a TSB (technical service bulletin) Not a recall

The bulletin states
Please make a copy of this bulletin and give it to your customer for future reference.

So I did

[3xHounds]

I had this done last Friday. I drove the car for the first time this morning, and nothing seems to have changed. Upon initial start-up noisy mushy brake pedal until the vacum builds up, which seemed to take as long or longer than it did before the "fix".

[willis]

3xHounds, Do you have a auto or a 5 speed? By the way I like your dogs.

[3xHounds]

Willis thanks for noticing my hounds, they are great company. I have an auto.

[SCVanguard]

I'm in the same boat as Hounds. In all honesty, it seems to me that it is taking longer now.

*sad face*

[Bogie]

Anyone with the fix notice any startup RPM changes.

[3xHounds]

Bogie,
I did not think to pay attention to the RPM prior to the change. I took the car in for an ck engine light that came on when I was returning from Pensacola this past Friday. Anyway as previously stated the service advisor requested permission to address the braking issue as long as the car was in the shop for the ck engine light, and I told him to go for it.

I drove the warm car home, but a week away from home required yard work etc., so I did not drive it until this morning.

I think I recall cold idiling around 1,200 RPM and my lack of patience caused me to depress the accelerator to reduce the high idle. I still had the noisy mushy break feel. Not sure if I am hyper sensitive here, but I perceive that it may be worse.

[Bogie]

Originally Posted by 3xHounds

Bogie,

I think I recall cold idiling around 1,200 RPM and my lack of patience caused me to depress the accelerator to reduce the high idle. I still had the noisy mushy break feel. Not sure if I am hyper sensitive here, but I perceive that it may be worse.

The next time you cold start it, check at what RPM it rises to on start, how long it stays there, and then what it initially drops to, followed by its final idle position. I'm guessing the normal design is a high idle followed by a low idle. The "fix" may rev it to a higher idle than high initially, followed by a drop to high idle, and then a drop to low idle. A quick jump to a higher idle than high, followed by a drop to high idle, would conceivable build a vacuum faster.

This is purely a guess, but a somewhat educated guess in that an engine can be made to produce vacuum faster if it is rev'd high and then throttled back.

Of course, there might be other ways, maybe there is a way to achieve the same result by playing with the valve overlap at idle.

[SCVanguard]

Recorded my numbers this morning after car sat for about 14 hours in my garage...

at startup, it got as high as 1500rpm for a second but settled in around 1400rpm.
After 30-45 seconds, rpms slowly dropped to 1000.
After touching the throttle, it dropped down to 750ish.

Hope that helps...

[SKY 4 ME]

Is overnight an extended period of time? Ohio is not considered "high eleveation" to my knowledge. Mine does this every morning I start it and back out of the garage. I'm used to it now, but what about down the road when I eventually sell it? I can see a prospective buyer having an issue with the brakes performing like this. I hope they come up with a fix and not an improvement to the condition.
SKY 4 ME

[Bogie]

Originally Posted by SKY 4 ME

Is overnight an extended period of time? Ohio is not considered "high eleveation" to my knowledge. Mine does this every morning I start it and back out of the garage. I'm used to it now, but what about down the road when I eventually sell it? I can see a prospective buyer having an issue with the brakes performing like this. I hope they come up with a fix and not an improvement to the condition.
SKY 4 ME

Overnight should be OK. I'm not much concerned about whether there is residual vacuum; I'm trying to figure out what GM is doing to create more vacuum. The only reason I need a "cold" start is the engine idle seems to change depending on engine temp. A warm start might not produce the vacumm-inducing change.

[mrdave]

I had the retrofit on my sky in January, while it made it a little better still far from safe or normal.

I just had the vehicle inspector for the BBB drive the car today will be interesting to see his report.

I wonder how the updates above apply when the retrofit has been done.

[MidniteBlues]

Well, I hate say this but ah, if the 09's have the same problem, I will pass on it and WILL NOT BUY A 09.. And that is the way it is.. Also it will piss me off ...