This bulletin applies to 2012-2014 Chevy Tahoe vehicles that exhibit unwanted grade braking, low power and/or a busy-shifting transmission. These issues may be caused by the BPP (brake pedal position) sensor not being learned correctly in the ECM.
To view BPP data in the ECM, use a Tech 2 scan tool. Select powertrain/Select engine type/engine control module/ data display / auto transmission data GDS (2014 models); module diagnosis/ engine control module/ data display/automatic transmission data.
Scroll down and view the following parameter:
BPP signal = applied or released (should read Released with brake pedal released)
BPP sensor = 0% to 100% (should read 0% with brake pedal released)
BPP sensor = varying voltage (should read near 1 volt (+/- .3 volt) with pedal released.
BPP sensor learned released position = voltage (should equal the BPP sensor voltage with pedal released)
With the brake pedal released, use the BPP sensor parameters to determine if the ECM has learned the BPP release position correctly. If the BPP sensor learned release position voltage does not match the BPP sensor voltage with the pedal in the released position, the ECM will need to have a BPP relearn performed. If the ECM will not perform a BPP sensor relearn, SPS program the ECM. After the ECM SPS programming is complete, the BPP will relearn.
