Revisions to this document are noted
by a stripe in the left­hand margin

SUBJECT:

SIL 01­EP­15, Rev. A
February, 2016
Page 1 of 48

Replacing SKiM Module and GATE Drive Card Inside the Dual Power Inverter Module 2 (DPIM2)

MODELS AFFECTED:

H 40/50 EP SystemTM Equipped With DPIM2

Tools Required
• J­51586 Tab Bending Tool
• J­46708 (or equivalent) Multimeter
• J­51673 DPIM Leak Tester
• Stop Watch
• Electrostatic Discharge Wrist Strap (Refer to Figure 2)
• Pick or Small Flat Blade Screwdriver
• Torx PlusTM T8 Bit
• Torx PlusTM T10 Bit
• Torx PlusTM T20 Bit
• Torx PlusTM T25 Bit
• Torx PlusTM T25 6in Bit
• 4mm Hex Key
• 6mm Hex Key
• 8mm Hex Socket
• Loctite® 242
• Loctite® 425

Introduction:
This Service Information Letter (SIL) announces the availability of the SKiM Module and GATE Drive Card Service
Kit (Electronic Service Kit P/N 29556119), GATE Drive Card Phase A­C Harness Service Kit (Harness Phase A­C
Service Kit P/N 29556137), and GATE Drive Card Phase B Harness Service Kit (Harness Phase B Service Kit
P/N 29556136) and includes the procedure to replace the SKiM Module and GATE Drive Card located inside
the DPIM2. The availability of these kits eliminates the need for a complete DPIM2 replacement under certain
failure conditions.

BC / SL7597EN

3112407

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

SIL 01­EP­15, Rev. A
February, 2016
Page 2 of 48
Phase A or C Replacement: Electronic Service Kit P/N 29556119 and Harness Phase A­C Service Kit
P/N 29556137 are required to perform the replacement of the Phase A or C SKiM Module and GATE Drive Card.
Phase B Replacement: Electronic Service Kit P/N 29556119 and Harness Phase B Service Kit P/N 29556136 are
required to perform the replacement of the Phase B SKiM Module and GATE Drive Card.
NOTE: Components and replacement procedures are the same for Inverter A and Inverter B. Refer to
Figure 25 for GATE Drive Card locations.
Refer to Table 1, Table 2, and Table 3 for Electronic Service Kit contents.
Table 1. SKiM Module and GATE Drive Card Electronic Service Kit
Part Name

Part Number

Quantity

29556119

1

Module­SKiM 5

29540527

1

GATE Drive Card

29546784

1

Busbar­GND, GATE Drive

29546790

2

SKiM Module O­Ring

29540585

1

Cover Gasket

29540714

1

SKiM Module Capacitor

29546783

3

Electronic Service Kit

Table 2. GATE Drive Card Phase A­C Harness Electronic Service Kit
Part Name

Part Number

Quantity

29556137

1

Cable Assembly

29546811

1

Strain Relief

29549697

2

*

1

Harness Phase A­C Service Kit

Ty Wrap
* Ty Wrap material to be nylon 6/6 or approved equivalent.

Table 3. GATE Drive Card Phase B Harness Electronic Service Kit
Part Name

Part Number

Quantity

29556136

1

Cable Assembly

29546810

1

Strain Relief

29549697

2

*

1

Harness Phase B Service Kit

Ty Wrap
* Ty Wrap material to be nylon 6/6 or approved equivalent.

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

SIL 01­EP­15, Rev. A
February, 2016
Page 3 of 48

NOTE: Perform the necessary diagnosis prior to ordering Electronic Service Kit P/N 29556119,
P/N 29556137, and P/N 29556136. Contact Allison TAC at (800) 252­5283 to confirm the SKiM Module
or GATE Drive Card failure.

Warranty Claim Information:
1. When a SKiM Module and Gate Drive Card Kit, P/N 29556119, is utilized to repair a failed DPIM under
warranty, use SKiM Module and Gate Drive Card Kit part number 29556119 as the PFP and claim the kit
part number in the Service Parts subsection of the AWAARE claim.
2. The replacement of SKiM Modules and Gate Drive Cards on a DPIM2 under Allison supplied warranty, must
be approved my Allison H 40/50 EPTM Service Engineering prior to removing the DPIM Main Cover.

Diagnosis:
Scenario 1: The SKiM Module and Gate Drive Card may need to be replaced if any of the following Diagnostic
Trouble Codes are logged and any of the red highlighted checks in Table 4 and Table 5 are out of specification.
• DTC 77­30
• DTC 80­01
Scenario 2: The SKiM Module and Gate Drive Card may need to be replaced if any of the following Saturation
Fault codes are logged and/or any of the red highlighted checks in Table 4 and Table 5 are out of specification.
• DTC 73­27
• DTC 74­27
• DTC 73­28
• DTC 74­28
• DTC 73­29
• DTC 74­29
NOTE: The saturation codes listed under Scenario 2 and the out of specification measurements in
Table 4 and Table 5 will identify which SKiM Module and IGBT need to be replaced.
If any of the DTCs listed in Scenario 1 and Scenario 2 are logged, troubleshoot them per H 40/50 EP SystemTM
Troubleshooting Manual TS5812EN. In addition to troubleshooting the aforementioned DTCs, a DPIM Check List
should be completed. Refer to the DPIM Check List appendix of the troubleshooting manual.
WARNING: DO NOT rely on the High Voltage Interlock Loop (HVIL) or control systems to de­energize
the system. Always perform the Electrical Disconnect Verification Procedure to be sure the system is
discharged before servicing components.
DO NOT attempt to bypass any High Voltage Interlock for any reason. Tampering with the HVIL may result
in injury. Failure to follow proper safety procedures may result in serious personal injury or death.

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

SIL 01­EP­15, Rev. A
February, 2016
Page 4 of 48

NOTE: Allison Transmission, Inc. requires that the DPIM be removed from the vehicle prior to component
replacement. Prior to removal of the DPIM, refer to the H 40/50 EP SystemTM System Troubleshooting
Manual (TS5812EN) and perform the Electrical Disconnect Verification Procedure.

NOTE: The SKiM Module and GATE Drive Card replacement should NOT be performed if smoke and/or
water damage are present.

NOTE: All cables (AC and DC) must be removed from the DPIM prior to taking measurements shown
on the DPIM Check List. For additional information, refer to H 40/50 EP SystemTM Troubleshooting
Manual (TS5812EN).

Table 4. Inverter Circuit Test – IGBT Check (DPIM1 and DPIM2)
DPIM Checklist V2.0
NOTE: To take these measurements, all cables (AC and DC) must be removed from the DPIM.
NOTE: The specifications listed below are merely guidelines. All DPIM replacements must be
approved by the Technical Assistance Center.
Inverter Circuit Test – IGBT Check (DPIM1 and DPIM2)
A­Side

Place
Negative
multimeter
lead on
DPIM
Chassis

B­Side

DC(+)

DC(­)

Phase A

Phase B

Phase C

Phase A

Phase B

Phase C

>400K
Ohms

>400K
Ohms

>200K
Ohms

>200K
Ohms

>200K
Ohms

>200K
Ohms

>200K
Ohms

>200K
Ohms

N/A

>7K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

N/A

N/A

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

>5K Ohms

—

—

Results
Place
Positive
multimeter
lead on
DC(+)
Results
Place
Negative
multimeter
lead on
DC(­)
Results

—

Set your multimeter to Resistance mode (Ohms).
Make sure multimeter lead polarity is correct during Resistance Check.
Resistance values will vary at first. Hold leads in position until the resistance value stabilizes and then record it.

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

SIL 01­EP­15, Rev. A
February, 2016
Page 5 of 48
Table 5. Inverter Circuit Test – Diode Test (DPIM1 and DPIM2)
Inverter Circuit Test – Diode Test (DPIM1 and DPIM2)
A­Side

Place Positive
multimeter lead
on DC(­)

B­Side

Phase A

Phase B

Phase C

Phase A

Phase B

Phase C

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

0.3V±0.1

Results
Place Negative
multimeter lead
on DC(+)
Results
Set multimeter to Diode Check mode.
Make sure multimeter lead polarity is correct during Diode Check.
This test uses a small current that is applied to the diode and the voltage drop is the reading determined above.

Figure 1. DPIM2 (Main Cover and Lug Box Covers Removed)

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

SIL 01­EP­15, Rev. A
February, 2016
Page 6 of 48

NOTE: Refer to the attachment at the end of this SIL for information regarding the name and location of
components within the DPIM2.

The procedures contained in this SIL are organized into the following sections:
Section 1: Removal of Main Cover and HVIL Circuit Card
Section 2: Removal of BCA Card Mounting Shelf
Section 3: Removal of the AC Busbar Assembly
Section 4: Removal of GATE Drive Card
Section 5: Measure Baseline DPIM Cooler Circuit Leak Rate
Section 6: Removal of SKiM Module
Section 7: Installation of SKiM Module
Section 8: Measure DPIM Cooler Circuit Leak Rate After SKiM Module Installation
Section 9: Inspection of the AC Busbar Supports for Corrosion and Debris
Section 10: Installation of GATE Drive Card