If that isnt happening then the SBA motor may need to be replaced. When you start the vehicle and get to around 10 mph you should hear a light buzzing noise, maybe even feel it in the brake pedal. It runs a self test every time you start the vehicle for 1 second, and if the IPC (instrument panel) does not see that the test completes 5 times in a row it turns on the "Service Brake Booster" message. That vehicle has whats called a supplemental brake assist motor, it is a extra vacuum pump to supply extra vacuum in low vacuum conditions such as accel or if the booster failed. Re: Service Brake Booster on DIC in '03 Tahoe I found a used one on EBAY, got lucky and it seems to work fine on the tahoe but won't run on the yukon. It is not avail from any dealer I could find or after market source. There has been some discussion about the instrument cluster needing to be re-flashed or programed, along with changing the Alternator with more or less amps or maybe a ground on the alternator? This little pump was only used for a couple of years on these models and the pump has now been discontinued. Is there any other ground any of you know about that may need cleaning? Has anyone else had the issue and solved it. This would help a lot to maybe source the lack of power to the unit. I can not find a WIRING DIAGRAM FOR EITHER VEHICLE. I have taken both grounds off below the driver's side frame rail, cleaned them and coated battery paste to keep corrosion down in the future. Evidently there is no power to this AVP unit upon startup, maybe a wire compromised, a Ground not tight somewhere, a elect. I know I have a working pump but evidently there is no power running to the pump to turn it on, so after a few seconds of the testing outlined below in Shadams post, the SBB light comes on again. When attached to the 03 Yukon, the pump will not purr much less run when the vehicle is started and the SBB light appears again on the cluster. This test was done with the used AVP or SBA pump sitting on the cowl as there is no need for ground on the pump, it has a male female connection of 6 wires I believe at the top of the AVP. When connected to the tahoe the used pump purrs and seems to work just fine sucking from the inlet hole that attaches to the brake booster. I have purchased a used (AVP or SBA pump) which I have plugged into my 03 tahoe which does not have a problem with SBB light. The below explanation of what caused the light to come on helps but does not address what issues I have and will share. I have sourced every thread I could find. The 03 Yukon has "SERVICE BRAKE BOOSTER" (SBB) light on when i bot the truck 6 months ago. I have and 03 tahoe with 139K and 03 Yukon with 90k.
4 circuit brake booxter full#
This post is from SHADAMS on the GM Inside News forum, so that full credit is given to this outstanding explanation this person should be commended. Vacuum pump(AVP) or (SBA) noted below attached to 03 Tahoe and 03 Yukon. I have no clue what the fix is since the mentioned post didn't include any solutions.īelow is an overview of the Aux. There seems to be a checklist the car is going through at startup and one of the items it checks is voltage in a wire from the 4-pin connector on the alternator to an electric vacum pump? Mine is 14.8 while I believe stock is 14.2-14.4. One post I saw somewhere said that a guy had a similar problem and he thought it was because some high output alternators have slightly higher volts. I've been googling this for quite some time but I have found very little info. I put the new one back in and the error message came back.
.jpg "4 circuit brake booxter")
The problem is related to the alternator swap since I put the old one back in this afternoon and the error message was gone. It failed the inspection because of the error message in the DIC though so I have to fix this now.
I had the car through the bi-yearly inspection today and the brakes ARE in fact good. It comes on every time I drive and wont go away until I push one of the steering wheel buttons.īrakes seems to work great. After starting up, everything is fine but as soon as I start driving I get this Service Brake Booster message in the DIC panel. I think the stock alternator was 130A.Īfter putting in the new alternator, my charging problems went away and it seems to have worked great during the cold winter months here in Norway. It was not performing as well as before so I bought a new Powermaster 220A unit. Problem started when I replaced the stock alternator a while ago. I have been searching this excellent forum but couldn't find an answer. I really could need some input on a problem on my 2003 Tahoe.
0 kommentar(er)
