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4.4.1 HDX Control Module

Dakota Digital HDX Control Module

Type: Digital Instrument Control Box

Model: HDX Control Module (Black)

Manufacturer: Dakota Digital

Manual: HDX System Manual

Overview

Main control box for HDX instrument system. Processes sensor inputs, BIM module data, and J1939 CAN bus signals to drive dashboard cluster display.

Mounting: HDPE panel on firewall behind dashboard

Power: PMU OUT9 (25A capacity, CONSTANT power)

Specifications

  • Dimensions: 5.5" W × 3.5" D × 1" H
  • Power Input: 12V DC (8-23V operating range)
  • Fuse Requirement: 5-20A max (per manufacturer specification)
  • Recommended Fuse: 10A (adequate for entire HDX system including BIM modules)
  • Current Draw: IGN Off ≈ 0.3mA, IGN On ≈ 250-750mA (confirms 10A fuse sizing)
  • BIM Ports: 3.5mm headphone jack (supports up to 16 BIM modules via daisy-chain)
  • Display Output: Proprietary cable to HDX dashboard cluster
  • Configuration: Bluetooth app (iOS/Android) for setup and diagnostics

Input Signal Thresholds:

  • Active High (HIGH, LEFT, RIGHT, GEAR, WAIT, DIM, EX+): Low ≤4V, High ≥8V
  • Active Low (Check/ENGINE, BRAKE, CRUISE, 4x4, EX-): Low ≤8V, High ≥9V
  • Tachometer: Normal mode 3-7.5V, Low-voltage mode 1-4V
  • Speedometer: Square wave >1.2Vp-p or sine wave >1.4Vp-p

Output Capabilities:

  • WARN, SPD outputs: <600mA max

Inputs

Included Sensors:

  • Water temperature sender (100-260°F)
  • Oil pressure sender (0-80 psi)

BIM Module Expansion:

  • J1939 CAN bus interface (BIM-01-2-J1939)
  • GPS speed/compass (GPS-50-2)
  • TPMS (BIM-22-3)
  • Compass/outside temp (BIM-17-2)

Fuel Level:

  • Factory TJ fuel level sender (variable resistance)

Wiring

Connection Pin/Wire Source Destination Notes
DIM ADJ - GND - - - Not used (dash dimming via DIM input instead)
DIM ADJ - SIG - - - Not used (dash dimming via DIM input instead)
FUEL INPUT - GND - Factory TJ fuel sender HDX fuel GND Sender ground
FUEL INPUT - SIG 18 AWG ✓ Factory TJ fuel sender HDX fuel SIG Variable resistance sender signal
PRESSURE INPUT - DRN - Included oil pressure sender HDX pressure DRN Included sensor - OR use J1939 oil pressure
PRESSURE INPUT - GND - Included oil pressure sender HDX pressure GND Included sensor - OR use J1939 oil pressure
PRESSURE INPUT - SIG - Included oil pressure sender HDX pressure SIG Included sensor - OR use J1939 oil pressure
PRESSURE INPUT - PWR - Included oil pressure sender HDX pressure PWR Included sensor - OR use J1939 oil pressure
TEMP INPUT - GND - Included water temp sender HDX temp GND Included sensor - OR use J1939 coolant temp
TEMP INPUT - SIG - Included water temp sender HDX temp SIG Included sensor - OR use J1939 coolant temp
SPEED INPUT - GND - - - Not used (GPS-50-2 provides speedometer via BIM)
SPEED INPUT - SIG - - - Not used (GPS-50-2 provides speedometer via BIM)
SPEED INPUT - PWR - - - Not used (GPS-50-2 provides speedometer via BIM)
CRUISE - - - Not used (no cruise control)
SPD OUT - - - Not used
TACH OUT - - - Not used
TACH WARN - - - Not used (J1939 provides tach via BIM-01-2)
TACH - - - Not used (J1939 provides tach via BIM-01-2)
IGNITION PWR 16 AWG Ignition bus bar HDX ignition input Switched 12V for ignition-controlled features
12 VDC CONSTANT 16 AWG ✓ Critical Cabin PDU Slot 2 HDX power input 10A fuse, CONSTANT power, ~2 ft
DIM 18 AWG ✓ Tail light circuit HDX DIM input Dash dimming control (variable voltage)
ENGINE 18 AWG ✓ ECM harness HDX ENGINE input Check engine light / MIL signal (active low)
BRAKE 18 AWG ✓ Brake switch or CT4 HDX BRAKE input Brake pedal indicator
HIGH 18 AWG ✓ CT4 high beam output HDX HIGH input High beam indicator
LEFT 18 AWG ✓ CT4 left turn output HDX LEFT input Left turn indicator
RIGHT 18 AWG ✓ CT4 right turn output HDX RIGHT input Right turn indicator
4x4/EX 18 AWG ✓ Transfer case switch HDX 4x4/EX input 4WD/4LO indicators
GEAR - BIM-01-2 J1939 - Gear position read from Turbolamik J1939 broadcast (no discrete input wiring)
WAIT/EX 18 AWG ✓ ECM harness HDX WAIT/EX input Wait-to-start indicator (active high)
EX - - - Reserved
EX - - - Reserved
WARN OUT - - - Not used
SWITCH INPUT - - - Not used (capacitive touch buttons on cluster)
DISPLAY CABLE Proprietary HDX control Dashboard cluster Factory harness included, ~2 ft
CLOCK CABLE - - - Not used (GPS-50-2 provides clock sync via BIM)
BIM I/O Proprietary HDX 3.5mm jack BIM modules Daisy-chain to 4 BIM modules (power + data)
Ground 16 AWG ✓ HDX ground Critical PDU ground bus Shared cabin ground, ~1 ft

BIM Module Integration

All BIM modules connect via single daisy-chain harness from HDX control 3.5mm port:

  • HDX Control → BIM-01-2-J1939 → GPS-50-2 → BIM-22-3 → BIM-17-2
  • Power and data carried over BIM/IO cables (no separate power wiring)
  • Modules auto-detect and configure via Bluetooth app

Outstanding Items

  • Determine 4WD/4LO indicator signal types (NP241 Rubicon transfer case outputs)
  • Determine brake indicator source (brake switch vs CT4 output)
  • Identify specific ECM harness pins for ENGINE (CEL) and WAIT signals