My Discovery 3 is almost 20 years old. These trucks were build very tough, however its the little things that are its weakness, at this age, things start to go brittle, after breaking a connector, I decided to try and find out what connector types are used and how to replace them.
After finding this really helpful Facebook group :
https://www.facebook.com/groups/4359499570789592
They were able to help identify the connector. (realized later the word sicma was printed on the side of the plug 🫠)
The wiring of a Land Rover Discovery 3 uses the Delphi SICMA connector family. SICMA is the Automotive Modular Interconnect System from Aptiv, formerly Delphi. This guide shows how to identify, repair, and source these connectors without a new loom.
What Is the Delphi SICMA System?
The SICMA system is a modular connector family for harsh automotive environments. It covers small signal connections and large power connections. It uses three standard terminal sizes.
- 0.64 mm terminals carry up to 11 A.
- 1.5 mm terminals carry up to 26 A.
- 2.8 mm terminals carry up to 46 A.
The crimp wire range is 0.13 to 5 mm². This equals 26 AWG to 10 AWG.
The SICMA Family Series
The family has nine series. Each series suits a specific place in the vehicle.
| Series | Terminals | Ways | Sealing | Typical Use |
|---|---|---|---|---|
| Mini-Sealed | 1.5 & 2.8 mm | 2, 3, 4, 5, 6, 6-mixed | IP67 & IPx9K | Body, chassis, engine compartment |
| Sensomate | 1.5 mm | 4, 5, 6 | IP68 & IPx9K | On-engine sensors and actuators |
| Inline Sealed | 1.5 & 2.8 mm | 6, 8, 24 | IP68, IP67 (24-way) | Exterior, chassis, engine compartment |
| Inline Unsealed | 1.5 & 2.8 mm | 2, 6, 10, 24, 36 | IP40 | Cockpit and dashboard |
| Panel Through (sealed & unsealed) | 0.64, 1.5, 2.8 mm | Up to 50 | IP40–IP67 | Door-to-body, firewall, battery bulkheads |
| Header Sealed Interconnect | 1.5 & 2.8 mm | 6, 24, 56, 90 | IP67 | Wire-to-PCB for ECUs |
| Sealed Relay Socket | 2.8 mm + 8 mm power | 8 | IP68 / IPx9K | Diesel pre-heating, comfort heating, EOBD |
| OBD | 1.5 mm | 16 | – | Standard diagnostic receptacle |
Key Design Features
These design features stop the common connector faults on the Discovery 3.
- TPA (Terminal Position Assurance) detects a terminal that is not fully inserted.
- CPA (Connector Position Assurance) confirms full mating of the connector halves.
- A mat seal keeps water out of the connector.
- One-piece clean-body terminals have no seam, so they do not tear the seals.
- The L-shape crimp suits 0.13 mm² wire.
- A reinforced pin resists bending during mating.
- The side-by-side insulation crimp barrel anchors the wire insulation.
- Mechanical color coding identifies the connector keying.
- The 2 to 6-way footprints are standard across OEMs.
- Mating force stays under 60 to 80 N.
Where You Find SICMA on a Discovery 3
- Engine bay harness sectioning uses Mini-Sealed or Inline Sealed connectors.
- On-engine sensors and actuators use Sensomate connectors.
- Door-to-body passes use Panel Through connectors.
- Cockpit and dashboard use Inline Unsealed connectors.
- The 16-way OBD port sits under the dash.
- Relay sockets live in the engine bay fusebox area.
The engine bay harness passes near the TDV6 injectors. The injector spill hose clips hold the spill pipes in this area.
The engine sensors use small sealed connectors. The upper thermostat temperature sensor is one example. The upper thermostat T-sensor hose feeds coolant to that sensor.
The AMK air suspension compressor uses a sealed inline connector. The AMK air suspension compressor mounts above the spare wheel.
Identify a Damaged Connector or Terminal
Find the housing part number on the embossed face of the housing. The color coding also points to the correct keying. Compare the number with the family list below.
- Mini-Sealed 2-way female: 10820158
- Mini-Sealed 2-way male: 10787262
- Mini-Sealed 6-way female: 10866615
- Sensomate 6-way: 33511993
- Inline Sealed 6-way female: 10723553
- OBD 16-way: 13800154
Terminal part numbers:
- 1.5 mm female terminal (0.35–0.70 mm²): 10863984
- 2.8 mm female terminal (0.35–0.70 mm²): 10781041
- 0.64 mm female terminal: 10811966
Repair a Connector, Not the Loom
You can replace one damaged housing or terminal. You do not need a whole new loom. Use the correct de-pin tool to release the terminal. Use a ratchet crimper for open-barrel terminals.
Check the TPA before you plug a connector together. A raised TPA means a terminal is not seated.
Search the Delphi or Aptiv part number on Mouser, Digi-Key, RS Components, Element14, or eBay. These parts cost much less than a dealer loom.
Download the Family Overview
Download: Aptiv SICMA Family Overview (PDF, 42 pages)
The technical data in this article comes from this document.
Summary
- SICMA is the Aptiv modular interconnect system, formerly Delphi.
- Terminal sizes are 0.64, 1.5, and 2.8 mm.
- Nine series cover the engine bay to the cockpit.
- Replace one terminal or housing; do not replace the loom.
- Check the TPA before you mate a connector.
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