SIL 09­EP­16
March, 2016
Page 1 of 6
SUBJECT:

Energy Storage System 3 (ESS 3) Release Notification

MODELS AFFECTED:

H 40/50 EPTM Transmissions

Effective June 2016, the Allison Transmission, Inc. will release the third generation of the Energy Storage System
(ESS3, P/N 29557378 & ESS3 CertPlus P/N 29557576) for the H 40/50 EPTM products. The first ESS3 serial
number will begin with 7010015001. The intention of this SIL is to introduce the ESS3 to the service channel,
describe the differences between the ESS2 and ESS3, and detail new service parts and procedures.
WARNING: Before replacing or repairing an ESS1, ESS2, or ESS3, perform the High Voltage Disconnect
Verification Procedure found in the H 40/50 EP System service manual SM3602.

Interchangeability
The differences between ESS2 and ESS3 are internal with the exception of some identifying stickers on the
ESS cover and HVIL covers (refer to Figure 1). A new System Identification Number (SID) must be Re­flashed
when an ESS2 is replaced with an ESS3. The connectors (high voltage and low voltage), pins, mounting points,
and external dimensions are identical between the ESS2 and ESS3 making them fully interchangeable assemblies.

Internal Changes
The major internal differences between the ESS2 and ESS3 include the number of BCIMs, new main relays,
number of current sensors, new junction board, and new internal low voltage harness. There are 3 BCIMs in the
ESS3 as opposed to 6 in the ESS2. The high and low side main relays are replaced by a single main relay part
number that is used for both high and low side switching. The new junction board is specific to the ESS3 as
is the new internal low voltage harness.

SM / SL7774EN

3060651

Copyright © 2016 Allison Transmission, Inc. All Rights Reserved.

SIL 09­EP­16
March, 2016
Page 2 of 6

Figure 1. Energy Storage System (ESS)

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SIL 09­EP­16
March, 2016
Page 3 of 6
The following instructions and Table 1 describe how to download the correct SID.
NOTE: If the requested SID is not available, contact TAC and request the SID be created.

TCM Assembly Number Breakdown:
SIDs are created based on hardware configuration and the application of system (for additional information
reference SIL 2­EP­08).
• The third through the seventh digits of a SID makeup the Transmission Control Module (TCM) Assembly
Number; the TCM Assembly Number can be broken down into two groups:
1. The fourth digit of the SID, second digit of the TCM Assembly Number, identifies the hardware
configuration of the system; 0­F (See Table 1)
2. The rest of the TCM Assembly Number digits are specific to the application

Figure 2. SID Breakdown
Table 1. Hardware Configuration
Hardware Configuration
SID Number

Engine

TCM/VCM Type

Inverter Type

Battery Pack

VV­XSXXX­YYY­Z

Pre MY 07

Pre­4th Gen

DPIM1

ESS3

VV­XTXXX­YYY­Z

Pre MY 07

Pre­4th Gen

DPIM2

ESS3

VV­XUXXX­YYY­Z

MY2007

Pre­4th Gen

DPIM1

ESS3

VV­XVXXX­YYY­Z

MY2007

Pre­4th Gen

DPIM2

ESS3

VV­XWXXX­YYY­Z

MY2010

4th Gen

DPIM1

ESS3

VV­XXXXX­YYY­Z

MY2010

4th Gen

DPIM2

ESS3

VV­XYXXX­YYY­Z

MY2013

4th Gen

DPIM2

ESS3

VV­XZXXX­YYY­Z

MY2016

4th Gen

DPIM2

ESS3

When an ESS1 or ESS2 is replaced with an ESS3, the SID must be updated so the 4th digit matches the new
hardware configuration of the system. The rest of the TCM Assembly Number portion of the SID should stay the
same, but all other digits may be different. For this reason, the new SID should be downloaded as a TCM Assembly
Number rather than a SID (refer to Figure 3). To download any SID by TCM Assembly Number, add a “HEV” prefix
to the TCM Assembly Number portion of the SID. If changing a vehicle’s hardware configuration, change the
second digit of the TCM Assembly Number based on Table 1.
Copyright © 2016 Allison Transmission, Inc. All Rights Reserved.

SIL 09­EP­16
March, 2016
Page 4 of 6

Figure 3. TCM Assembly Number
Example: A technician is working on a bus with the SID 64­G0001­002­U, Pre MY07, Pre 4th Gen, DPIM1 and an
ESS1. The technician determines that the ESS1 must be serviced with an ESS3. After installing the ESS3 the
technician would need to reflash the entire vehicle (TCM, VCM, DPIM, and ESS) with the SID VV­XS001–YYY­Z
to match the vehicle’s new hardware configuration.
NOTE: The SIDs required for an ESS2 to ESS3 replacement will be released AS NEEDED. Use
TCM Reflash to verify that the new SID is available before obtaining authorization for an ESS3 from the
Technical Assistance Center (TAC). If the required SID is not yet available, inform TAC when requesting
authorization for the ESS3.

Parts Information:
Assembly Serviceability
With the release of the ESS3 all ESSs should be serviced with an ESS3, P/N 29557378 or ESS3 CertPlus
P/N 29557576. Service Information Letter (SIL) 21­EP­08 describes identifying the need to order a replacement
ESS and the requirements necessary prior to placing an order. As with the ESS2, authorization must be obtained
prior to ordering a service ESS3. Contact TAC if you believe an ESS1, ESS2, or ESS3 requires replacement.
Component Serviceability
The same components that are serviceable in an ESS2 are serviceable in an ESS3. However, most components are
not interchangable between the ESS2 and ESS3. Table 2 describes the part differences between ESS2 and ESS3.
The parts listed in Table 2 are new for ESS3 and are not interchangeable with the former ESS2 parts. Figures 6
and 7 illustrate BCIM differences.
Table 2. ESS3 Parts
Former ESS2 Parts

Current ESS3 Parts

Part Number

Description

Part Number

Description

29550667

Thermistor Assembly, No. 1

29558095

Thermistor Assembly, No. 1

29550668

Thermistor Assembly, No. 2

29550896

Thermistor Assembly, No. 2

Copyright © 2016 Allison Transmission, Inc. All Rights Reserved.

SIL 09­EP­16
March, 2016
Page 5 of 6

Table 2. ESS3 Parts (cont’d)
Former ESS2 Parts

Current ESS3 Parts

Part Number

Description

Part Number

Description

29550669

Thermistor Assembly, No. 3

29558097

Thermistor Assembly, No. 3

29550670

Thermistor Assembly, No. 4

29550671

Thermistor Assembly, No. 5

29556072

Thermistor Assembly, No. 6

29550673

Battery Controller Interface
Module (BCIM)

29558054

Battery Controller Interface
Module (BCIM)

29542856

Harness Wiring, Low Voltage

29558053

Harness Wiring, Low Voltage

29542847

Relay Assy ­ Main High Side

29558066

Relay Assy, Main

29542848

Relay Assy ­ Main Low Side

29558066

Relay Assy, Main

29542850

Sensor Assy ­ Current

29558059

Sensor Assy ­ Current

NOTE: Although the ESS2 and ESS3 BCIMs look identical, they have different software. It is important to
install the correct BCIM during a repair. Failure to do so will set an active 76­61 Battery Subpack Software
ID code and shut down the vehicle’s high voltage system. The only way to correct this scenario is to install
the correct BCIM. As seen in Table 3, BCIMs can be identified by either their Allison or Panasonic P/Ns
prior to installation. Refer to Table 3 and the interchangeability section of this SIL to identify whether you
are working on an ESS2 or an ESS3. The software levels of ESS2 and ESS3 are subject to revision, but
the middle digit of the software will always remain the same: "2" for ESS2 and "3" for ESS3.

Figure 4. ESS3 Battery Controller Interface Module (BCIM) P/N 29558054

Copyright © 2016 Allison Transmission, Inc. All Rights Reserved.

SIL 09­EP­16
March, 2016
Page 6 of 6
Table 3. BCIM and Software Identification
ESS Generation

Allison BCIM P/N

Panasonic BCIM P/N

Software Level

ESS1

29549707

EV­EHSOR01C

E19

ESS2

29550673

EV­EER03A

E27

ESS3

29558054

EV­EEH02ADG1

E30

Figure 5.
ESS1 BCIM P/N 29549707 With E19 Software

Figure 6.
ESS2 BCIM P/N 29550673 With E27 Software

Figure 7.
ESS3 BCIM P/N 29558054 With E30 Software

ESS3 Storage:
Maximum shelf life for an ESS3 is 12 months (same as ESS2). Shelf life is affected by storage temperature.
Detailed storage guidelines and maintenance charge procedures can be found in the ESS Service Manual SM4162
Section 1­7.
NOTE: For initial receipt of an ESS3, assume several months of shipping/logistics timing and incorporate
into the shelf life maintenance schedule. The complete date (manufacturing date) of an ESS can be found
using the S/N search function of Unit History. Unit History is found under the Warranty tab of the initial
Allison Transmission Extranet screen.

Copyright © 2016 Allison Transmission, Inc. All Rights Reserved.