View Full Version : Mileage changed after changing Suspension Control Module

05-02-10, 02:24 PM
Almost done with upgrade of 2007 Ext to 2009 Magnetic Ride Control. Changed all the shocks to MR's, and then changed Suspensions Control Module above the spare tire to a 2009 model with 9 miles. Have not changed the Body Control Module yet but have one. Anyway, after changing the SCM my mileage changed to 71,000 + from the 41,000+ it had been. I recognize that I will have to have the dealership properly program all these modules after all the physical changes are all made to align VIN, Stabiltrack, TPMS etc. But was surprised that mileage would change. Now I am concerned that when I change the BCM that my radio and perhaps my ECU will not work. Does anyone know the interrelationships and if the truck will still run after the BCM is changed?

Big Windy Ext
05-03-10, 04:51 AM
I thought (think)BCM is vin locked , you may get around that if you have the bcm with the Vin already , I don't think anything horrible happens , I wanted to change an ecu on a diesel , the bcm was the stinker . Keep posted the Magnetic ride changeover is interesting , damn you and your auto porn :thumbsup:

05-03-10, 08:56 AM
Wow.. definitely keep us posted on this swap.. very interesting.. Just hope you don't run into any more GM junk about can't do this or that!

Big Windy Ext
05-03-10, 10:40 AM
Preach your as bad as me with this stuff .

05-03-10, 11:37 AM
oh yea! You know it..

Big Windy Ext
07-21-10, 07:48 AM
TTT Waterking (almighty king of swap ) Any progress on the Magnetic ride ?

07-21-10, 03:39 PM
Waterking, you might found out already...

When replacing the BCM, the car will not start without proper Tech2 programming. There is a lot of communication, data exchange and keyword exchange. Additionally a BCM will come "naked" without the needed calibrations. Itīs just like buying a new computer without operation system installed.

The Tech2 and TIS2WEB will be needed to get the right calibration to your new BCM.

After the right calibration is installed, you must relearn the retraints IDs. Basicaly a data exchange between the BCM and the Airbag Control Module.

The important thing is that after installing the new BCM, the car will not run anymore, untill programmed. So you can not drive to a dealer!


07-23-10, 07:58 AM
Got everything installed i.e MR shocks, Aux suspension module (by the spare tire), 9.5 rear assembly, Baer Eradispeed rotors, EBC yellows, GF Spindle/spring lowering kit, new lower A Arms, 24" Bazo wheels with, Hotchkiss sway bars, Edelbrock lower rear trailing arms and panhard rod, Platinum front fascia with Led headlights. Did not do BCM. All alarms on: ABS, Service Suspension, Stabiltrack, Air bag. Had it aligned last Monday. Took to dealer (different one) on Tuesday.....After waiting all day finally got an hour on the computer...

Air bag...door modules unplugged and plugged all them back in and it cleared

Service suspension...Bad exhaust valve in compressor...

Stabiltrack...Cleared dtc and it did not return

ABS....Cleared dtc.....I had a small brake leak in rear brake line which may have caused this.

Left dealer $82 lighter but with Service suspension alarm...replaced compressor when I got back home to clear this. Auto leveling now works.

Wed: removed rear axle because of movement and rubbing in the front of rear well....and tires would just touch front lower trailing arm mounting bolt and bracket under stress even though I had clearanced them. UPS arrived with Edelbrock arms and Panhard rod. Fedex with 1/4" rear spacers.

Thur: redrilled upper and lower trailing arm mounting holes on axle to move axle 1/4" rearward. Installed Edelbrock Arms. Then after about three hours of effort...totally exhausted got the Panhard rod on. The mounting bracket on the rear assembly was too tight to get the bushing in. Pry, bend (or try to), torch, pound....lost about three pounds in sweat (107 deg). Put 1/4" spacers on in rear. Fix brake fluid seep in RR line.

Fri: Tested OK. Auto leveling working but a little lower because upper trailing arms moved down slightly. Put DJM shock extenders on rear....Service suspension alarm came on....Took shock extenders back off (a real PITA to get shocks compressed enough to go in original holes). Service suspension went back off. Talked to sheriff while picking up tools. Took shower/changed clothes, threw suitcase/tools in bed of truck, and at 1630 drove truck non-stop from AL to Akron, OH. Arrived 0430 in the morning, lost hr due to time shift. 21.2 MPG (ECM had been previously programmed for these tires (35.5") by BlackBear and was dead on according to road radar indicators).

Sat: Family reunion Sun: Sleep. Mon: Check engine comes on, Autozone says it reads out as Oxy sensor, ignore and head for North Carolina mountains to pick up son 0800 Tue. Light goes out when leaving their parking lot. 1530 arrive Atlanta visit cousin. 1830 arrive Home in NW Alabama. Drive by local grocery store 2 miles from house Service suspension alarm comes on, followed by Stabiltrk, then engine light. Park in driveway. Collapse in bed.

Total 1890 mi., 36.4 hours driving time, 20.8 MPG (only 19.8 in mountains) overall. Could have gotten better gas mileage WITHOUT using cruise so much and driving slower but was tired and in a hurry most the time. My cruise is most aggressive and will often downshift twice on a hill. No rubbing, excellent ride, bluetooth VCIM from CTS worked flawlessly, replacement heated washer fluid module worked great, Led headlights are more than adequate, burned some paint off hats of rotors. Have not done anything to it since parked...have had other things to do and used 2008 for them.

Will check into the new codes sometime in the next week.....I really think I have to check all the grounding circuits and alternator because I often get low voltage alarms on my Radar detector.

Big Windy Ext
07-23-10, 08:13 AM
How does it ride ? I'm too old to work in 107 F, your a nut lol !!! It is a sickness taking apart a perfectly working auto and modifying it . Thanks for the update !

07-23-10, 09:09 AM
I am too old for this too. There is no bounce back like when younger...it is more like a crawl back. Had hand and arm cramps so bad that thought I might not be able to drive. The ride was great....even the alignment guy was really impressed, best riding big wheel/tire truck he had driven. Smoother than 2008 with 22's. Have a slight steering wheel vibration but I think that is the steering shaft thread lube issue many GMT900 people have addressed by unbolting, moving up and down splined shafts and rebolting. Still have to recheck the pinion angle and may make adjustments to the driveline angles which to me seem excessive at 7 down on transfer case with 6 up on the rear pinion. I do get what feels like rear wrap under hard acceleration. Heavy wheels/tires (100lbs 50/50 tire/wheel) make for slower acceleration/deceleration but once moving practically like driving on glass. Still an occasional rub in front liner and tires touch Hotchkiss sway bar in the front at lock. Was carrying 400lbs of tools and the spare 24" wheel in bed (regular spare does NOT fit and 24" will not fit under vehicle YET). Handling seems improved but hard to tell which was the most effective because of the number of changes made at once. I do know the Hotchkiss bars made a significant difference when installed on the 2008. I prefer the ride and handling of this modded 2007 over the 2008 but have not had the chance to fully evaluate and compare it to a stock 22" MR vehicle. The ride is softer than the 2008 but have to consider that might be because the MR shocks might not be working at all. So, this is NOT considered a success until I can do some back to backs hard handling runs with it unloaded. I was afraid to break something during the trip so did not push it.

Big Windy Ext
10-08-10, 04:49 PM
How has this mod panned out ?

10-08-10, 05:53 PM
man I am tired just from reading what you have done....I am just going to drive mine like it is :)

10-10-10, 08:27 PM
You really have me interested in this swap for my ESV. I've replaced a couple of ESC modules in Escalades for 5v reference problems and never had the odometer change even after reflashing them with TIS2WEB. I will check to see if there is any correlation between the modules. Possible GMLAN (communication) issue?

11-14-10, 04:49 PM
man I am tired just from reading what you have done....I am just going to drive mine like it is :)
^Yea, what he said!