Figure 46. SKiM Module Thread Boss

5. Verify that all four (4) sides of the SKiM Module are flush with the DPIM chassis to ensure that the SKiM
Module O­Ring has not been pinched.
6. Verify that all fifteen (15) spring pins are in place (refer to Figure 47).

Figure 47. SKiM Module Spring Pins (Quantity 15)

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7. Using a Torx PlusTM 6in T25 bit, install the fourteen (14) M5x14mm screws (refer to Figure 48). Torque the
screws to 3.1­3.5 N∙m (27.4­31.0 lb in.).
CAUTION: Do not damage the white insulation on the DC busbar while installing the screws to secure the
SKiM module. Damage to insulation can cause permanent damage to the DPIM.

Figure 48. SKiM Module Fastener Locations

Section 8: Measure DPIM Cooler Circuit Leak Rate After SKiM Module Installation
NOTE: All DPIM Leak Testing equipment should still be in place (refer to Section 5: Measure Baseline
DPIM Cooler Circuit Leak Rate).
1. Connect the hose end of J­51673 to the Quick Disconnect Fitting on the DPIM.
2. Open the J­51673 Flow Valve and adjust the Pressure Regulator until the pressure stabilizes at 25 psi (refer
to Figure 49).

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February, 2016
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Figure 49. DPIM Leak Tester J­51673
3. Close the Flow Valve and start Stop Watch.
4. After five (5) minutes elapse, record the pressure.
NOTE: The pressure drop should be within 0.5 psi of the baseline pressure drop obtained in Section 5:
Measure Baseline DPIM Cooler Circuit Leak Rate. If the pressure drop is above 0.5 psi from the baseline,
then the SKiM Module O­Ring may have been damaged during the installation of the SKiM Module.
Remove the SKiM Module and inspect the O­Ring and sealing surfaces for damage. Any damaged
components should be replaced.
5. If the pressure drop exceeds 0.5 psi from the baseline reading pressure drop, repeat Section 7: Installation of
SKiM Module and Section 8: Measure DPIM Cooler Circuit Leak Rate After SKiM Module Installation.
6. Remove the DPIM Leak Tester J­51673, Port Plug and Quick Disconnect Fitting from the DPIM.

Section 9: Inspection of the AC Busbar Supports for Corrosion and Debris
NOTE: Corrosion and debris that has fallen into the AC Busbar Support can create an isolation fault
between the AC Busbar and DPIM Chassis
1. Using a Torx PlusTM T20 bit, remove the four (4) M4x22mm screws retaining the two (2) AC Busbar
Supports (refer to Figure 50).

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SIL 01­EP­15, Rev. A
February, 2016
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Figure 50. AC Busbar Supports
2. Remove the Busbar Supports and clean any debris inside the DPIM chassis or on the components. Replace
components if excessive corrosion or damage is found. A vacuum may be used to remove any debris from
the DPIM.
3. Install the two (2) AC Busbar Supports and use a Torx PlusTM T20 bit to install the four (4) M4x22mm screws
(refer to Figure 51). Torque the four (4) M4x22mm screws to 1.2­1.5 (10.6­13.3 lb in.).

Figure 51. AC Busbar Supports

Section 10: Installation of GATE Drive Card
1. Bend the six (6) DC Busbar Terminal Tabs back down using Tab Bending Tool J­51586.
2. Install AC Busbar and Current Sensor Assembly and apply one drop of Loctite® 425 or 242 thread locking
compound to the end of the external threads of the two (2) M5x18mm mounting screws. Using a Torx PlusTM
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SIL 01­EP­15, Rev. A
February, 2016
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T25 bit, install the two (2) M5x18mm mounting screws to the AC Busbar (refer to Figure 52). Torque the two
(2) M5x18mm screws to 3.1­3.5 N∙m (27.4­31.0 lb in.).

Figure 52. AC Busbar Mounting Screw Locations
3. Perform the following step ONLY if removal of the Encoder Module was required:
Carefully position the Encoder Module on the DPIM. Using a Torx PlusTM T20 bit, install the four
(4) M4x14mm screws (refer to Figure 53). Torque the four (4) M4x14mm screws to 1.2­1.5 N∙m
(10.6­13.3 lb in.).

Figure 53. Encoder Module Installation

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SIL 01­EP­15, Rev. A
February, 2016
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4. Position the three (3) capacitors on the SKiM Module. Apply one drop of Loctite® 425 or 242 thread locking
compound to the ends of the external threads of the three (3) M6x12mm screws. Using a 4mm hex key,
install the three (3) M6x12mm screws (refer to Figure 54). Torque the three (3) M6x12mm screws to 6.8­7.3
N∙m (60.2­64.6 lb in.).

Figure 54. SKiM Module Capacitor Installation
Loctite®

5. Apply one drop of
425 or 242 thread locking compound to the ends of the external threads of the six
(6) M6x10mm screws. Using a 4mm hex key, install the six (6) M6x10mm screws to the SKiM Module (refer
to Figure 55). Torque the six (6) M6x10mm screws to 6.8­7.3 N∙m (60.2­64.6 lb in.).

Figure 55. SKiM Module Fastener Locations
6. Position the GATE Drive Card to its mounting location. Carefully press the GATE Drive Card straight down
over the ten (10) white locking tabs (refer to Figure 56).

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SIL 01­EP­15, Rev. A
February, 2016
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Figure 56. GATE Drive Card Locking Tab Locations
7. Place the two (2) grounding brackets into position. Using a Torx PlusTM T10 bit, install the four (4) M3x8mm
(fine thread) screws to the GATE Drive Card (refer to Figure 57). Torque the four (4) M3x8mm (fine thread)
screws to 0.6­0.8 N∙m (5.3­7.1 lb in.).

Figure 57. GATE Drive Card Fastener Locations (M3x8mm Fine Thread) – Quantity 4

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SIL 01­EP­15, Rev. A
February, 2016
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8. Using a Torx PlusTM T8 bit, install the twelve (12) M3x8mm (coarse thread) screws to the GATE Drive Card
(refer to Figure 58). Torque the twelve (12) M3x8mm (coarse thread) screws to 0.3­0.6 N∙m (2.7­5.3 lb in.).

Figure 58. GATE Drive Card Fastener Locations (M3x8mm Coarse Thread – Quantity 12)

Section 11: Installation of the AC Busbar Assembly
1. Carefully install the AC Busbar Assembly into AC Lug Box (refer to Figure 59).
CAUTION: Do not allow the AC Busbar Assembly to strike the HVIL Switch during the installation process.

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SIL 01­EP­15, Rev. A
February, 2016
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Figure 59. Installation of AC Busbar Assembly

2. Install the HVIL switch connector (refer to Figure 60).

Figure 60. HVIL Switch Location

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SIL 01­EP­15, Rev. A
February, 2016
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3. Install and finger tighten the three (3) M8 AC lug bolts (refer to Figure 61).

Figure 61. AC Lug Bolts

4. Apply one drop of Loctite® 425 or 242 thread locking compound to the end of the external threads of the six
(6) M5x22mm screws. Using a Torx PlusTM T25 bit, install the six (6) M5x22mm screws (refer to Figure 62).
Torque the six (6) M5x22mm screws to 3.1­3.5 N∙m (27.4­30.9 lb in.).
NOTE: Install all screws before torquing to ensure that the holes line up.

NOTE: Exercise special care to not pinch any wires when components are installed and screws are
torqued.

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February, 2016
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Figure 62. Mounting Screw Locations

Section 12: Installation of BCA Card Mounting Shelf
1. Feed all ty wraps through the BCA Card Mounting Shelf (refer to Figure 63).

Figure 63. BCA Card Mounting Shelf Ty Wrap Location

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SIL 01­EP­15, Rev. A
February, 2016
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2. Replace the ribbon harness (1, 2, or 3) that connects to the Gate Drive that was replaced.
NOTE: P/N 29546811 is used on phases A and C and P/N 29546810 is used for Phase B (refer to
Figure 64).
3. Place the BCA Mounting Shelf onto the side of DPIM chassis as shown in Figure 64.

Figure 64. BCA Mounting Shelf (GATE Drive Card Cable Connectors Shown Circled)

4. Connect three (3) GATE Drive Card Connectors to three (3) GATE Drive Cards (refer to Figure 65) and
install the cable strain relief caps.

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SIL 01­EP­15, Rev. A
February, 2016
Page 43 of 48

Figure 65. GATE Drive Card Cable Connector Installation (BCA Card Cable Connector Shown for Clarity)

5. Move BCA Mounting Shelf to its final location. Using a Torx PlusTM T25 bit, install the seven (7) M5x14mm
screws that secure the BCA Mounting Shelf (refer to Figure 66). Torque the seven (7) M5x14mm screws to
3.1­3.5 N∙m (27.4­31.0 lb in.).

Figure 66. BCA Mounting Shelf Fastener Locations
6. Install five (5) wire harness connectors to circuit card surface mount connectors (refer to Figure 67,
Figure 68, and Figure 69).

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SIL 01­EP­15, Rev. A
February, 2016
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Figure 67. Wire Harness Connector Removal (4 Locations)

Figure 68. Current A, Current B, and Current C Locations
NOTE: Each current sensor phase (A, B, and C) MUST be plugged into the appropriate connector
(CURR A, CURR B, CURR C).

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

SIL 01­EP­15, Rev. A
February, 2016
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CAUTION: Permanent damage to the H 40/50 EP Drive UnitTM or DPIM can occur if the current sensor
harnesses are plugged into the wrong connectors.

Figure 69. Wire Harness Connector Installation

7. Install NEW wire ties to retain the wire harnesses (refer to Figure 70).

Figure 70. Wire Tie Locations

Section 13: Installation of HVIL Circuit Card and Main Cover
1. Insert one (1) new wire tie into the new HVIL Circuit Card at the same location as shown in Figure 71.

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SIL 01­EP­15, Rev. A
February, 2016
Page 46 of 48

NOTE: To ease assembly, the new wire tie must be inserted through the hole in the circuit card prior to
installation in the DPIM Housing.

Figure 71. HVIL Circuit Card – Wire Tie Location
2. Install HVIL Circuit Card into the DPIM Housing.
NOTE: Ensure that the wire harnesses and individual wires are NOT pinched under the circuit card
during installation.
3. Connect the three (3) wiring harness connectors at locations shown in Figure 72.

Figure 72. HVIL Circuit Card – Three (3) Harness Connector Locations

4. Using a Torx Plus™ T25 bit, install and finger tighten the ten (10) M5 screws that secure the HVIL Circuit
Card to the DPIM Housing. Torque all M5 screws to 3.1­3.5 N∙m (27­31 lb in). Refer to Figure 73 for
fastener sizes and locations.

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

SIL 01­EP­15, Rev. A
February, 2016
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Figure 73. HVIL Circuit Card – Fastener Sizes/Locations

5. Install the two (2) wire ring terminals onto the studs at locations shown in Figure 74. Using an 8mm socket,
install four (4) M5 nut/washer assemblies onto the studs as shown in the same figure. Torque the nuts
to 3.1­3.5 N∙m (27­31 lb in).

Figure 74. HVIL Circuit Card – Four (4) Mounting Nut/Washer Locations (M5)
6. Secure wiring with new wire ties and clip excess length as required. Refer to Figure 71 and Figure 75 for
wire tie locations.

Figure 75. HVIL Circuit Card – Two (2) Wire Tie Locations
7. Install new Cover Gasket P/N 29540714, included in Electronic Service Kit P/N 29556119. Using a Torx
Plus™ T25 bit, install and finger tighten the twenty­six (26) M5x18mm machine screws that secure the Main
Cover to the DPIM Housing as shown in Figure 76. Torque the screws to 3.1­3.5 N∙m (27­31 lb in).

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

SIL 01­EP­15, Rev. A
February, 2016
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Figure 76. DPIM Main Cover
NOTE: For additional information refer to H 40/50 EP SystemTM Service Manual SM3602EN Appendix E.

8. Complete the DPIM check sheet again to verify the repair before installing the DPIM on the bus.

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

DC
Terminal
Block

DC Lug
Box

AC Lug Box
Inverter B

AC Lug Box
Inverter A

AC Terminal
Block (x2)

AC Busbar (x6)

Diode
Inverter B

Diode
Inverter A

DC Busbar

Level 3

Current
Sensor (x6)

Level 1

BCA Card
Inverter B

BCA Card
Inverter A

X-Capacitor
(x18)

HVIL
Circuit
Board

HVIL
Switch

NOTE: This illustration is to be used for identifying the name and location
of components within the Dual Power Inverter Module 2 (DPIM2). It is not
intended to be used for disassembly and assembly procedures.

HVIL
Switches

Copyright 2014 Allison Transmission, Inc. All Rights Reserved.

Levels of Assembly

DPIM2

C

A

B

B

Level 2

Gate Drive
Cards
Inverter B

Phase

Phase

Gate Drive
Cards
Inverter A

Level 4

DC Capacitor SKiM Module/IGBT
(x9)
Cards Inverter B

SKiM Module/IGBT
Cards Inverter A

Encoder
Motor B

Phase

Phase

HVIL Support

Discharge
Resistor

DC Choke

Encoder
Motor A

A

C

AC Bus Bar
Inverter B

Phase

Phase

AC Bus Bar
Inverter A

GN7499EN
201405

Signal
Interface