ISSUE DATE:
SERVICE BULLETIN SUBJECT:
VINs or MODELS AFFECTED:
COMPLETE BY:
SERVICE BULLETIN #:
LABOR OPERATION CODE:

8-11-2020
Duopower Powertrain Software Update
Service Specified Buses
Next Service Opportunity
SC-20-115
PP41Z

NOTICE! It is expected that this process will require 1 hour per bus. Please
schedule appropriately to minimize vehicle downtime.

POWERTRAIN SOFTWARE UPDATE
Description

This procedure updates the Powertrain software to the latest version for improved powertrain
performance. A White Paper showing an overview is provided at the end of this document.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

1|Page

Summary of Software Changes
Improvements
1. Increased allowed regen torque to improve efficiency.
2. Increased allowed motoring torque to improve acceleration and gradeability.
3. Increased regen in default Drive and Low modes to promote more efficient driving. Previous
calibrations are still available using Proterra Diagnostic Tool configurations.
4. Various calibration changes to improve pedal response time, reduce drivetrain induced jerk in
certain conditions, and improve low speed “clunk” during pedal tip-in.
5. Revised startup and shutdown sequence to improve robustness to quick ignition (key) cycles.
6. Regen re-enable criteria post ABS event revised to allow re-enable without coming to a stop.
7. Revised shutdown criteria to allow for ECU to shut down when a transmission is stuck in gear.
8. Modified oil pump control to provide flow to both transmissions at the highest rate needed for
either transmission to protect against possibility of oil pump connectors being swapped.
9. Shifts selector display logic revised to only display “D” if a single forward mode is allowed to
improve driver interface.
10. Recalibrated loss of communication with body controller diagnostic (SPN 2033, FMI 9) to reduce
nuisance faults.
11. Recalibrated low power diagnostic (SPN 3357, FMI 1) to eliminate false positives under certain
startup conditions.
12. Revised motor torque diagnostic (SPN 9061 and 9062, FMI 0) to reduce potential for false
positives.
13. Modified transmission output speed diagnostics (SPN 191 and 9481, FMI 2) to reduce false
positives
New Features
1. Implemented acceleration limiting with modes for Eco, Nominal, and Max.
2. New motor check when drivetrain is enabled to ensure torque accuracy. Note, the motors are spun
during the test and may be heard. Shifting is prohibited (flashing shift selector display) until test is
complete; approximately 5 seconds after the drivetrain is enabled.
3. Support for motor and inverter pairing via Proterra Diagnostic Tool for field inverter or motor
replacements.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

2|Page

Bugs
1. Fixed bug inhibiting a change to allowed forward operating mode configuration.
2. Corrected torque application calibrations for reverse to match drive.
3. Recalibrated accelerator pedal input to ensure ability to reach 100% pedal position.
4. Corrected issue that would clear stuck in gear diagnostic when Proterra Diagnostic Tool was
active.
5. Fixed issue allowing rapid torque application when releasing the interlock with the accelerator
pedal depressed.
6. Revised torque application to eliminate motors spinning in neutral in certain operating conditions.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

3|Page

Tools/Parts Required
•
•

Customer Service Laptop with Proterra Diagnostic Tool
Nexiq USB Link2 Device

Parts Required:
•

054999

SOFTWARE, POWERTRAIN, 800V, DuoPower, v1.3.0

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

1 EA

4|Page

Connect to the Vehicle to Start the Proterra Diagnostics Tool

This process will guide the user to connect to the vehicle with the Proterra Diagnostics Tool.
1. Turn ON the 12/24V rear Vehicle Master Disconnect located behind the vehicle curbside rear
charge port access panel.
2. Turn ON the bus Master Run Switch at the Driver's Workplace and ensure the Dash screen is
ON to display “KEY ACC”.
Master Switch
“ACC”

3. Open the Streetside wheel well box to access to the OBDII Port.

OBDII Port

4. Power up (boot) the Proterra-supplied laptop containing the Proterra Diagnostic Tool.
5. Connect the Nexiq USB Link2 device to the laptop and to the appropriate OBDII Diagnostic
Port.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

5|Page

6. On the laptop, double-click on the Proterra Diagnostics Tool software icon to
start the software.
7. When the program opens, read and click OK for the prompt.
8. On the Home tab, select the appropriate device from the drop down and click “Connect”.

9. Once the diagnostic tool has connected to the vehicle, you will have a VIN number and
connection status displayed on the home screen, and tabs available to navigate.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

6|Page

Update Powertrain Software

This procedure updates the Powertrain software version and maintains the Powertrain parameter
configuration data across the flash download of new software.
1. Ensure you have the latest software file 054999.hex in a known location on the service
technician’s computer (Folder or Desktop).
IMPORTANT! NEVER access the software from a remote server or from a USB memory device,
ALWAYS copy the software files to your computer hard drive and access the software from this
location. It is recommended that you copy the entire “service bulletin files” folder to your local machine
in order to more effectively keep track of the software versions you are deploying:
\\bus.local\files\Engineering\Service Bulletins\Service Bulletin Files for SC-20-115\
2. Turn ON the 12/24V rear Vehicle Master Disconnect located behind the vehicle curbside rear
upper access panel.
3. Turn ON the bus Master Switch at the Driver's Workplace and ensure the Dash screen is ACC.

Master Switch “ACC”

4. After connecting to the vehicle using the Proterra Diagnostic tool at the front OBDII Port
(SSWW Box), navigate to the Configuration Tab.
5. Wait at least 10 seconds after starting the tool, then click the “Get Parameters” button at the
top of the page.
a. NOTE: This ensures that we have a backup copy of the original configuration
parameters stored in a “zip” file, contained in the C:/Logs folder on your
computer in case we need to refer to it later.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

7|Page

6. Click on the “SOFTWARE VERSION” button at the bottom left of the screen. Verify that the
Body Controller Software is version 6.3.0.
Note: If it is not Proterra Service Campaign SC-20-91 must be performed on the vehicle before
proceeding.

Click Software
Version

7. Now we are ready to click the Powertrain Firmware “Start Flash” Button.

Click Powertrain Start Flash

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

8|Page

8. The following screen will be displayed. Navigate to the location where you stored the
configuration file earlier. Select the software file downloaded previously and click “Open” to
load the file.
Note: The file name displayed should be 054999.hex.

Select File
Click “Open”

9. The Proterra Diagnostic Tool will attempt to connect to the device.

10. When the software update begins, the following screens will be displayed.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

9|Page

11. The software update may take several minutes to complete. When the update is complete the
following will be displayed. Click the “OK” button to complete the update process.

12. On the main screen, click the “Configuration” Button.

Click Configuration

13. The following screen will appear. Click on the “Get Parameters” button to download information
for the vehicle. Allow a few seconds for the information to populate the screen.

Click Get Parameters

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

10 | P a g e

14. Once the screen has populated, sort the values alphabetically by clicking on the “Name”
heading on the list.

Click Name

15. Scroll through the list to find the “EP_usi_ZR32_PerformanceMode_x”. Click on the name of
this parameter. See the “Proterra Powertrain Configuration Overview” on page 13 of this
document for a description of this parameter.
16. A screen similar to the following appears. The difference is the parameter name. The name
should be “EP_usi_ZR32_PerformanceMode”.

17. Enter a 0 in the “New Value” box and hit the “Write Button”.
18. Scroll through the parameter list to find the “EP_usi_ZR32_AllowedRNDLConfiguration_xx”
EEPROM value. See the “Proterra Powertrain Configuration Overview” on page 13 of this
document for a description of this parameter.
19. Update the “EP_usi_ZR32_AllowedRNDLConfiguration_xx” value to 3.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

11 | P a g e

20. The software update is now complete.
21. Disconnect the cable from the OBD-II port.
22. Close the Streetside wheel well box
23. Return the bus to service.

Headquarters: 1815 Rollins Road, Burlingame, CA 94010
East Coast Manufacturing: 1 Whitlee Court, Greenville, SC 29607
West Coast Manufacturing: 383 Cheryl Lane, City of Industry, CA 91789

12 | P a g e

PROTERRA POWERTRAIN
CONFIGURATION OVERVIEW
1. Objective
To describe the different acceleration performance modes and regenerative braking configurations for the Proterra
800V bus platform ProDrive and DuoPower powertrain. To provide an understanding of how these configuration
options impact range and energy economy.

2. Discussion
The Proterra powertrain system comes with the ability to configure the vehicle acceleration and deceleration drive
feel to meet the customers’ needs. These settings can be changed through the Proterra diagnostic tool when
connected to a vehicle. There are two main drive feel settings:
-

Performance Mode: This mode will change the maximum allowed vehicle acceleration rate
Regenerative Braking Configuration: This selection will adjust the aggressiveness of regenerative braking
when not accelerating (drivetrain-based braking)

2.1 Performance Mode
Proterra offers 3 distinct acceleration performance modes to tailor maximum vehicle acceleration to the customers’
requirements. The three modes are called: Eco, Nominal and Max performance. These modes can be configured
through the Proterra diagnostic tool variable EP_usi_ZR32_PerformanceMode_x (ECO= 0, Nominal= 1, Max= 2).
The driver cannot change these modes real time through a button or switch.
Table 1 below shows the maximum achievable acceleration for each performance mode under peak motor conditions
(no thermal derates). Proterra utilizes different acceleration limits to vary the performance of the vehicle. These
acceleration limits will modulate torque to the drivetrain by monitoring the actual acceleration rate. If the acceleration
rate of the vehicle approaches the limit, the traction inverter will reduce torque to ensure the limit is adhered to.
Acceleration limits primarily influence the vehicle speed below 30 MPH. Above 30 MPH, the vehicle speed is dictated
by the power capability of the drivetrain. It is important to note that regardless of the performance mode, the
powertrain will allow full power under scenarios where the acceleration limit is not being achieved. This is most
critical under hill climb conditions. Therefore, the acceleration limit and performance mode will not impact vehicle
gradeability performance.
Proterra recommends using the ECO Performance Mode (EP_usi_ZR32_PerformanceMode_x = 0) to maximize the
efficiency of the vehicle.

Speed
(MPH)
0
10
20
30
40
50
60

APTA
Eco Mode
Whitebook ProDrive
time (s)
0
5
10
18
30
60
-

time (s)
0
4.3
8.5
13.7
26.2
38.8
54.8

Eco Mode
DP
time (s)
0
3.8
8.3