Bulletin No.: PIT5206G
Published date: 06/12/2020

Preliminary Information
PIT5206G Unwanted Grade Braking, Low Power, and/or
Transmission Busy Shifting / P057B, P057C, and/or P057D
Product Investigation Review Required
Models
Brand:

Model:

Model Years:

VIN:
from

to

Engine:

Transmissions:

Cadillac

Escalade Models

2012 - 2020

All

All

All

All

Chevrolet

Avalanche

2012 - 2013

All

All

All

All

Chevrolet

Express Van

2012 - 2020

All

All

All

All

Chevrolet

Silverado

2012 - 2018

All

All

All

All

Chevrolet

Silverado LD

2019

All

All

All

All

Chevrolet

Silverado 2500/3500

2019

All

All

All

All

Chevrolet

Suburban

2012 - 2020

All

All

All

All

Chevrolet

Tahoe

2012 - 2020

All

All

All

All

GMC

Savana Van

2012 - 2020

All

All

All

All

GMC

Sierra

2012 - 2018

All

All

All

All

GMC

Sierra Limited

2019

All

All

All

All

GMC

Sierra 2500/3500

2019

All

All

All

All

GMC

Yukon Models

2012 - 2020

All

All

All

All

Supersession Statement
This PI was superseded to update the Model Year. Please discard PIT5206F.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition / Concern
Some owners may comment of any/all of the following issues:
-

Unwanted grade braking when NOT going down a grade
Reduced/Low engine power with no DIC messages (Brake Pedal Override Feature)
Transmission busy or frequent up and down shifts
DTC's P057B, P057C, and/or P057D may or may not be set

These issues may be caused by an incorrect Brake Pedal Position (BPP) sensor input to the
ECM. If the ECM is reading the brake pedal as being applied, when it is not, these issues
may occur.
Note: The BPP sensor assembly has two completely separate internal sensors contained in
one physical component. Each internal sensor can be compared to an old style Throttle
Position Sensor (5v ref, Low ref, signal). The BPP sensor has 6 total circuits, three of the
circuits (5v ref, Low ref, signal) connect to the BCM and the other three circuits (5v ref, Low
ref, signal) connect to the ECM, see example wiring diagram below. The concerns outlined in
this PI are with the three circuits that connect the BPP to the ECM.

Recommendations / Instructions
The purpose of this PI is to help with finding the BPP data parameters in the scan tool, and
also to provide some additional diagnostic help.
1. To view the BPP data in the ECM, use the scan tool and build the vehicle as follows:
Tech 2 (2013 and older models): Powertrain/ Select Engine Type/ Engine Control Module/
Data Display/ Auto. Transmission Data
GDS2 (2014 and newer models) : Module Diagnostics/ Engine Control Module/ Data Display/
Automatic Transmission Data
2. Once the correct data list has been selected, scroll down and view the parameters listed
below. These parameters can help determine what value the ECM has learned for the brake
pedal learned released voltage and what the actual BPP voltage is according to the ECM.
With the brake pedal released, the actual "BPP Sensor" voltage should equal, or be very
close to what the "BPP Sensor Learned Released Position" voltage is.
BPP Sensor (%) = 0% to 100% (should read "0%" with brake pedal released)
BPP Sensor (Voltage) = Voltage (typical voltage with pedal released is approximately 1 volt
+/- .3 volt)
BPP Sensor Learned Released Position = Voltage (should equal the BPP sensor voltage with
pedal released)
Note: NOT ALL ENGINE TYPES WILL HAVE ALL OF THE PARAMETERS LISTED ABOVE.
3. Once the ECM has learned the "BPP Sensor Learned Released Position" voltage there is
no reason that this voltage should ever change. But the ECM is continuously monitoring the
BPP sensor voltage for a value which is lower than the "BPP Sensor Learned Released
Position" voltage. If there happens to be an intermittent wiring/connection issue which
caused the BPP sensor voltage input to the ECM to drop below the previously learned
voltage, the ECM will learn this new lower voltage. After the intermittent wiring/connection
issue corrected itself, the "BPP sensor" voltage may NO LONGER equal the "BPP Sensor
Learned Released Position" voltage when the brake pedal is released. Example, the
new "BPP Sensor Learned Released Position" voltage may be .61 volts and the "BPP Sensor"

voltage 1.02 volts with the brake pedal released. This would cause the ECM to think the
brake pedal is applied, when in fact, it is not. This may cause the truck to go into an
unwanted grade braking event, low engine power due to the brake pedal override feature,
transmission busy shifting, etc.
If an ECM BPP sensor relearn is performed, the truck may be temporarily repaired until the
intermittent wiring issue between the ECM and BPP sensor occurs again. If this happens,
the ECM will once again learn the wrong "BPP Sensor Learned Released Position" voltage. A
vehicle exhibiting this concern may lead a technician to believe the ECM is not retaining the
"BPP Sensor Learned Released" value and cause him to unnecessarily replace the ECM.
Typically, if the ECM is intermittently learning a lower "BPP Sensor Learned Released
Position" voltage it is cause by an issue with the BPP 5 volt reference circuit 5359 or the
BPP signal return circuit 5361.
The most common areas for any of the BPP circuit issues on the Full Size trucks are:
New body style trucks (2014 and newer)
- Inline connector X115
- Inline connector X119/X315 (Connector number varies with vehicle build; refer to SI. This is
a 16-way green connector mounted to the bottom of the X61A Junction Block - Instrument
Panel.)
Old body style trucks (2014 and previous)
- Inline connector X205
4. When looking up the ECM BPP relearn procedure in SI, there will be one relearn
procedure for the BCM and another one for the ECM. Make sure you are using the ECM
relearn procedure, examples below. Also, in some cases when performing the ECM BPP
relearn, the ECM may not learn the "BPP Sensor Learned Released Position" voltage or there
is no relearn procedure listed. In these cases, make sure that with the brake pedal released,
the BPP sensor voltage is a typical voltage reading of approximately 1 volt +/- .3 volt. If the
voltage is typical and the ECM will not perform a relearn or there is no relearn procedure
listed, try SPS programming the ECM. The ECM will then learn the actual BPP sensor voltage
as the "BPP Sensor Learned Released Position" voltage.
Example SI Doc ID: 2655204 (old body style) and 2535744 (new body style).

Warranty Information
The correction for this concern may be any one of several repairs described above. For
vehicles repaired under warranty, please use the appropriate warranty labor operation based
on the actual cause and repair.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.

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