Deutsch ASU Connectors (Micro UltraLite Series) are compact, high-performance motorsport sensor connectors — 30% lighter than a mated Deutsch ASL pair and 17% smaller coupling ring, built to the same IP67, MIL-spec-derived environmental standards. Available in 3-way and 5-way layouts with shell size 3, the ASU series is widely used in GT3, GT, WRC, R5, and LMP applications wherever minimising connector weight and envelope size is a priority without compromising on sealing or contact reliability.
XTRA Motorsport stocks the complete Deutsch ASU range — plugs (body style 6), in-line receptacles (body style 1), and oval flange bulkhead receptacles (body style 0) — in both 3-way and 5-way layouts, across all six keyway colours: N, A, B, C, D, and E. In EU stock — dispatched via DHL/UPS across Europe.
Technical Specifications
Property
3-way (03-03)
5-way (03-05)
Series
Micro UltraLite (ASU)
Micro UltraLite (ASU)
Shell size
3
3
Number of positions
3
5
Contact size
22
24
Rated current
5 A per contact
3 A per contact
Wire range
22–28 AWG
24–30 AWG
IP rating
IP67
IP67
Shell finish
Conductive black zinc
Conductive black zinc
Contact material
Gold-plated copper alloy
Gold-plated copper alloy
Insert sealing
Interfacial wire sealing, bonded and sealed
Interfacial wire sealing, bonded and sealed
Body Styles
Code
Body Style
Description
0
Oval Flange Receptacle
Panel / bulkhead / firewall mount — two-hole bolt-down flange
1
In-Line Receptacle
Free-hanging inline receptacle for harness-to-harness connections
6
Plug
Free-hanging plug, mates onto body style 0 or 1 receptacle
The first digit of an ASU part number is the body style code: ASU003 = bulkhead, ASU103 = in-line, ASU603 = plug.
Keyway Colour System
Six keyways prevent mis-mating between sensor circuits. The keyway letter appears immediately before the contact type suffix — for example ASU603-05SA-HE = keyway A, socket contacts.
Keyway
Band Colour
Notes
N
Red
Dedicated or high-priority circuit
A
Yellow
General sensor — most common (throttle, pressure, lambda)
B
Blue
Second sensor circuit
C
Orange
Third sensor circuit
D
Green
Fourth sensor circuit
E
Grey
Fifth sensor circuit
U
Violet
Universal — plug (body style 6) only; mates with any keyway receptacle
U (Universal / Violet) keyway: A U-keyed plug mates with any other keyway receptacle (N, A, B, C, D, or E). Available on the plug (body style 6) only — there is no U-keyed ASU receptacle.
Shrink Boot Compatibility
The ASU series shell size 3 housing has a built-in shrink boot lip on the rear for strain relief and environmental sealing of the wire bundle exit. Confirmed compatible boots:
All listed boots are designed for shell size 3 connectors and feature a small J-port cable exit — keeping the recovered wire bundle tight against the connector body. Note that ASU shell 3 boots (G03 variants) are not the same as ASL shell 6 boots and cannot be substituted between series.
Part Number Guide
Deutsch ASU part numbers follow a consistent structure:
GT3 / GT / WRC / R5 / LMP — where lower weight is the priority
ASL and ASU are not interchangeable — different shell sizes, different contact P/Ns, different boots. Choose ASL when the application requires shell size 6 or a U-keyed universal plug. Choose ASU when minimising weight and envelope size is the priority and both sides of the connection can be specified fresh.
Motorsport Applications
Deutsch ASU connectors are widely used in:
GT3 and GT racing — 3-way and 5-way ASU connectors are widely used for throttle position, MAP, oil pressure, coolant temperature, and other low-current sensor circuits; shell size 3 reduces weight and harness bulk in sensor-dense areas around the engine
WRC, R5, and R2 rally — widely used in rally harness builds where weight reduction is part of the build brief; the keyway system prevents sensor mis-connection during rapid service-park harness changes
LMP and prototype endurance — used in LMP builds and ACO/FIA WEC-adjacent prototype series where mass and packaging drive connector selection
ECU and PDM sensor inputs — compatible with all major motorsport ECU and PDM platforms referencing Deutsch Autosport circular sensor interfaces (Pi, MoTeC, AiM, Bosch)
Firewall bulkhead transitions — body style 0 (oval flange) provides a sealed, compact harness penetration at the firewall with the same IP67 integrity as the cable-side connectors
Weight-critical harness builds — used where every gram in the wiring harness contributes to a weight target; 30% lighter per mated pair vs ASL accumulates meaningfully across a full car harness
European stock — dispatched to your workshop: XTRA Motorsport holds Deutsch ASU connectors — plugs, bulkhead receptacles, in-line receptacles, and size 22/24 contacts — across all key keyways in EU stock. Standard EU delivery via DHL/UPS.
FAQ
What is the difference between Deutsch ASL and ASU connectors?
Both are MIL-spec-derived motorsport sensor connectors from the Deutsch Autosport circular series. ASL (MicroLITE) is shell size 6, 5-way only, size 23 contacts at 3 A. ASU (Micro UltraLite) is shell size 3, available in 3-way and 5-way, and is 30% lighter per mated pair with a 17% smaller coupling ring. The two series are not interchangeable — different shells, contacts, and boots.
What wire gauge do Deutsch ASU connectors accept?
It depends on the arrangement. 3-way (03-03) connectors use size 22 contacts rated for 22–28 AWG. 5-way (03-05) connectors use size 24 contacts rated for 24–30 AWG. PTFE-insulated wire (Tefzel / M22759) is standard for motorsport sensor circuits.
Are Deutsch ASU connectors IP67 rated?
Yes. The bonded and sealed insert with interfacial wire sealing delivers IP67 environmental protection across all body styles — plug, in-line receptacle, and bulkhead receptacle.
What crimping tools do I need for ASU contacts?
Crimp tool M22520/2-01 for both contact sizes. Positioner depends on arrangement and contact type: 3-way sockets use 605464, 3-way pins use 605463; 5-way sockets use 605840, 5-way pins use 605839. Insertion/removal: M81969/14-01 (Green/White) for 3-way size 22 contacts; 605837 (Orange/White) for 5-way size 24 contacts.
What heat shrink boots fit Deutsch ASU connectors?
Shell size 3 boots only. Confirmed fits: Raychem 204W221-25-G03-0 (straight), 224W221-25-G03-0 (90°); HellermannTyton 1037-4-G (straight), 1182-4-G (90°). Do not use ASL shell 6 boots — wrong size.
Does the ASU series have a U (Universal) keyway?
Yes — the U keyway is available on ASU plugs (body style 6) only. A U-keyed plug mates with any keyway receptacle (N, A, B, C, D, or E), making it the standard choice for test harnesses and service-park diagnostic rigs. There is no U-keyed ASU receptacle. Contact XTRA Motorsport for current availability of U keyway ASU plug variants.
Where can I buy Deutsch ASU connectors in Europe?
XTRA Motorsport stocks Deutsch ASU connectors — plugs, bulkhead receptacles, in-line receptacles, and size 22/24 contacts — in all major keyways, with delivery across the EU from EU stock via DHL/UPS.
