Strange fluctuations in Scan Master

tallor

Member
Joined
Aug 17, 2010
My TPS is fluctuating from .30-.46. My voltage and PU as also fluctuating (volts 11.6-12.2). The fluctuations are pretty fast 2-3 per second. this is with the key 0n - motor off. TPS also fluctuates the same with the motor running. I disconnected the wires to the alternator thinking that I could possibly be a bad voltage regulator. No change with key on. I did start the car to see if it made a difference. I also hooked up the power logger to see if I had the same readings (making sure the scanner is not bad). Same readings. Installed a new TPS - same fluctuations. Swapped out chips in the ECM - no change. Bad ECM?
 
Last edited:
Time to bring out the multimeter and start back-probing wires.[/QUOTE

I have done it extensively. Pulled the fuse on the radio and eliminated the power to the amp (looking for feedback). I can not find any voltage fluctuations. It seems to be coming out of the ECM.


On Oct 18, 2014, at 2:40 PM, BOOST! <boostupdate@turbobuick.com> wrote:
Turbo Buick Forum | Buick Grand National | T-Type | Turbo T
tallor, 87geeinnreplied to a thread you are watching at Turbo Buick Forum | Buick Grand National | T-Type | Turbo T.

Strange fluctuations in Scan Master

Time to bring out the multimeter and start back-probing wires.


I have done it extensively. Pulled the fuse on the radio and eliminated the power to the amp (looking for feedback). I can not find any voltage fluctuations. It seems to be coming out of the ECM.
 
Top