Description

Dearborn DPA 4, DPA 4 Plus, DPA 5, DPA II, DPA III 2012 Technical Manual

If you have ever wasted an hour chasing a no-communication fault because you trusted a third‑party pinout diagram, you know exactly why this manual exists. I have seen technicians fry a DPA 5 quad‑CAN adapter by backfeeding power on the wrong pin — a mistake that disappears when you use the actual Dearborn factory data. This 2012 Technical Manual covers the DPA 4, DPA 4 Plus, DPA 5, DPA II, and DPA III protocol adapters. It is 18 pages of verified pin assignments, connector drawings, and the J1939 Type‑2 connector reference. Not a PDF of someone’s guesswork — original OEM documentation.

DPA 4 and DPA 5 Series Pinout Tables

The core of this manual is a set of color and black‑and‑white tables that map every signal on every DPA variant. For the DPA 4/4 Plus, for example, you get pin‑by‑pin assignments for ground, power (9–32 VDC), J1708+, J1708−, CAN1 Hi/Lo/Shield, CAN1 termination resistors, SW CAN, ALDL/GM UART (pin 16 on DPA 4, pin 1 on DPA 4 Plus), 9141 K‑Line (pin 1), L‑Line (pin 11), J1850 Hi (pin 5), and discrete outputs (pin 11). The manual also lists CAN2 and CAN3/CAN4 for the Quad‑CAN DPA 5. If you are building a custom breakout cable or troubleshooting a flickering J1939 network, this table is the only reference you should touch. Page 2 of the manual shows all the cross‑model comparisons in one view.

What Connectors Are Covered?

Beyond the DPA pinouts, the manual contains a full “Industry Connectors Reference Guide” that includes the J1939 Type‑2 connector. That connector is common on modern heavy‑duty trucks and off‑road equipment, and the manual gives you the exact pin layout — no need to hunt through SAE standards. It also covers the standard 9‑pin Deutsch connector used for J1708 and the various CAN connectors. For anyone working on Drogobych Crane КТА-16, КТА-25, КТА-28 2004 Installation Manual electrical systems that use the same protocols, this pinout data is a direct cross‑reference.

18 Pages of Factory Pinout Data

Let me be blunt: you are not going to find this level of detail in a forum post or a generic wiring diagram book. These 18 pages were written by Dearborn’s engineers and revised in 2012. The document date is 01/09/12, revision 2.0. Every table footnotes which pins belong to which DPA model. The DPA 5 Dual CAN/BT, DPA 5 Quad CAN, DPA 4/4 Plus, and DPA 4 Dual CAN all have separate columns. The DPA II and DPA III are listed as separate variants with their own connector assignments. When you need to know whether pin 2 on a DPA 5 Quad CAN carries CAN3 Lo or CAN3 Shield, this manual answers without ambiguity. That is the difference between a working interface and a dead adapter.

J1939 Type‑2 Connector: Factory Spec

The manual devotes a full section to the J1939 Type‑2 connector, which is often mispinned in aftermarket guides. Dearborn includes the correct pin numbers for CAN_H, CAN_L, shield, termination, and power. If you are installing a DPA on a truck with a J1939 network, you must verify your harness against this diagram. A single miswire can take out the entire backbone. And for vehicles equipped with a Manual Transmission, the CAN bus carries transmission control messages — a wrong pinout here means no TCM communication.

Get the Right Pinout Before You Probe

Before you connect a DPA 4 Plus to a customer’s engine ECU, pull the manual out. Match the adapter’s endplate markings (e.g., “/T”, “/MH”) to the table. The manual notes that older DPA 4 and 4 Plus units were pinned according to those markings — do not assume they match the newer DPA 5 layout. I keep a printed copy in my laptop bag. You should too.

Who Needs This Manual?

This is for technicians who diagnose heavy‑duty vehicles with Dearborn protocol adapters. DIYers who build their own J1939 test stands will also benefit. If you have ever been stuck trying to read a diesel ECU because your DPA was wired wrong, this 18‑page document saves you the headache. It is also useful for engineers who need to verify CAN pinouts in a lab environment. For more heavy‑duty manuals, see the Injectocean Diablo, Murciélago, Defender, Discovery, Freelander Technical Manual and the Minsk MMVZ-3.11212 Technical Manual – Factory Specs.

Source Authenticity: OEM vs. Aftermarket

Aftermarket wiring books often reprint pinout tables from the 1990s without checking for updates. This manual is original Dearborn Group documentation — copyright 2012, publication revision 2.0. The disclaimer on page 1 states it is for reference purposes, but the pinout data matches what we find on actual DPA adapters in the field. I have cross‑checked it against three different DPA 5 units. It is correct. Do not trust a forum when you have the factory print.

Does this manual cover the DPA 4 Plus?

Yes. The pinout table includes a column labeled “DPA 4/4 Plus” that lists all signals for that adapter.

What years of vehicles does this apply to?

The manual was published in 2012, so it covers connectors and protocols up to that date. For older J1708 systems (pre‑2000), the pinout data still applies because the DPA adapters were designed to support legacy protocols. However, the J1939 Type‑2 connector section is specific to 2002+ heavy‑duty On‑Board Diagnostics (OBD) implementations. If you are working on a 1998 truck, the J1708 and J1850 data remains valid; just ignore the J1939 section.

Can I use this manual for a DPA II?

Yes. The DPA II and DPA III are listed as separate variants in the pinout tables. The manual includes columns for “DPA II” and “DPA III” where applicable. Note that the DPA II does not support CAN2 or higher channels, so the corresponding pins are left blank. The manual clearly marks these omissions.

How do I verify the pinout on my actual adapter?

Look at the endplate marking on your DPA unit. The manual says: “DPA variants up to and including the DPA 4 Plus were pinned out according to the printing on the DPA endplate (i.e. ‘/T’, ‘/MH’, etc.).” Find the matching entry in the table. For example, a DPA 4 with “/MH” uses the ALDL/GM UART on pin 1, while a DPA 4 Plus uses the same pin for 9141 K‑Line. If you are still unsure, call DG technical support (the phone number is on page 2). Manual transmission diagnostics often require precise CAN wiring, so this verification step is not optional.

Stop relying on photocopied diagrams that shift pins by one. The factory spec is here. Access the Factory Manual and keep it next to your oscilloscope.