Hardware & Pinouts
MCU, connector specs, J1/J2 pinout tables, and OBD connection wiring for the Lucas 5AS.
Hardware
- MCU: Motorola MC68HC05B16 marked
ZC99399CFN,Lucas 53873483,OD650J - J1 (large connector): TE Multilock 26-pin,
174516-6 - J2 (small connector): TE Multilock 12-pin,
173851-1
Pinout
Signals marked * exist only on 98MY versions of the 5AS.
J1 — 26-pin grey connector
| Pin | Description | I/O | Active |
|---|---|---|---|
| 1 | Ignition Sense | I | HIGH |
| 2 | Battery − (Main Supply) | — | LOW |
| 3 | 3TH Diagnostic Input | I | LOW |
| 4 | Driver's Sill Up | I | LOW |
| 5 | Passenger's Sill Up | I | LOW |
| 6 | Passenger / Rear Doors Open | I | LOW |
| 7 | Driver's Door Open | I | LOW |
| 8 | Horn Relay | O | LOW |
| 9 | MEMS ECU Link | O | LOW |
| 10 | Aerial | I | — |
| 11 | CDL Unlock Motor | O | HIGH |
| 12 | 3TH Output | O | LOW |
| 13 | CDL Lock Motor | O | HIGH |
| 14 | Volumetric Sensor Power | O | HIGH |
| 15 | Diagnostic Ground | — | LOW |
| 16 | Diagnostic Comms In | I | LOW |
| 17 | LED | — | LOW |
| 18 | Bonnet Open Switch | I | LOW |
| 19 | Driver's Sill Down | I | LOW |
| 20 | Volumetric Sensor Signal | I | LOW |
| 21 | Boot Open Switch | I | LOW |
| 22 | Key Barrel Switches | I | LOW |
| 23 | Crank Relay | O | LOW |
| 24 | Diagnostic Comms Out | O | LOW |
| 25 | Chime | O | LOW |
| 26 | Battery + (Main Supply) | — | HIGH |
J2 — 12-pin white connector
| Pin | Description | I/O | Active |
|---|---|---|---|
| 1 | Superlock Motors | O | HIGH |
| 4 | BBUS Status * | O | LOW |
| 6 | Hazard Flash Right | O | HIGH |
| 7 | Hazard Flash Left | O | HIGH |
| 8 | Volumetric Program | O | LOW |
| 9 | Inertia Switch | I | HIGH |
| 10 | Courtesy Lamp(s) * | O | LOW |
| 11 | Energiser Coil Signal * | O | LOW |
| 12 | Energiser Coil Power * | O | HIGH |
Pins 2, 3 and 5 are not connected. Early 5AS units have only the grey (J1) connector.
Connection
RX/TX at 12 V logic level with inverted RX. A CH340 VAG-KKL cable works: solder the RS232 pin to VCC to invert RX.
On the MGF's OBD port the K-line pins differ from standard — 1 and 3 instead of 7 and 15 — so an adapter is needed.