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2.9.4 GPS-50-2 (GPS Speed/Compass Module)

Dakota Digital GPS-50-2 Module

Type: GPS Speed Sender / Compass / BIM Module

Model: GPS-50-2

Manufacturer: Dakota Digital

Product Page: GPS Speed/Compass Sender/BIM

Manual: GPS-50-2 Manual

Overview

GPS-based speedometer, compass, altimeter, and clock sync module. Eliminates need for transmission speed sensor - works with any transmission, transfer case, or gear ratio.

Mounting: HDPE panel on firewall (behind dashboard)

Power: Via BIM/IO cable from HDX control box (no separate power wiring)

Specifications

  • Dimensions: 4.75" W × 2.75" D × 1" H
  • Speed Range: 0-158 MPH (255 km/h)
  • Update Rate: 10 times per second
  • Accuracy: ±0.1 MPH (GPS-dependent)
  • Output Signals: 4k, 8k, 16k PPM (selectable)
  • Signal Types: Sine wave or square wave (configurable)
  • Current Draw: Negligible — bus-powered via the HDX BIM/IO cable (no separate feed); draw is included in the HDX system budget on PMU OUT9 (25A cap, ~12A typ). Dakota Digital publishes no per-module current for these data modules (only power modules like the BIM-RGB, 7.4A, list a figure).
  • Antenna: Integrated omni-directional (optional external antenna available)
  • Warranty: 2 years

GPS Antenna

Integrated Antenna:

  • Built-in omni-directional antenna
  • Mounting: Dash top or windshield area

Optional External Antenna:

  • Part Number: 600041
  • Use if integrated antenna location has poor sky view
  • Extended cable for remote mounting

Critical System - Sky View Required

GPS speedometer is legally required for on-road operation. Ensure antenna has clear view of sky for reliable GPS signal. Obstructions (metal dash, windshield tint, etc.) may degrade signal quality.

Wiring

Connection Source Destination Wire Gauge Notes
Constant Critical Cabin PDU Slot 4 (TBD #144) GPS-50-2 power 18 AWG ✓ BIM CONSTANT power — may be bus-powered via BIM/IO cable instead
BIM/IO HDX control box GPS-50-2 input Proprietary Data via daisy-chain
GPS Antenna GPS-50-2 module Dash/windshield mount Coax cable Included antenna cable
Outside Temp GPS-50-2 (optional) SEN-15-1 probe Sensor wire If used instead of BIM-17-2

Antenna Routing:

  • GPS-50-2 on firewall HDPE panel → antenna cable → dash top or windshield mount
  • Route cable through dash for clean installation
  • Avoid routing near high-current wires or ignition system

Outstanding Items

🔴 Critical (2)

High (7)

📋 Medium (3)

  • Horn button → PMU In 1 wiring path through steering column (#152) — PMU In 1 (horn request) lists "steering wheel button" as its source, and the horn page puts the button on the steering-wheel PTT bracket — but no wire path, gauge, or connector is defined for how the button contact reaches PMU In 1 through/around the steering column. Street-legal item with an under-specified signal path.
  • iBooster Wiring Harness Selection (#105) — Select the Bosch iBooster (Gen 2) wiring harness: Tulay's Gen 2 universal (plug-and-play) vs EVcreate Gen 2 connector kit (DIY). Decision pending donor arrival and pigtail condition inspection. Tracked in the purchase tracker but was missing a TBD issue.
  • Axle Brake Flex Hose Length (#86) — DOT (FMVSS 106) braided-stainless extended-length flex at each axle - length blocked on axle + suspension selection (Section 10); size to full droop, do not cut until ride height fixed

🔍 Verify (5)

  • iBooster standby current spec (ignition-off test value) (#151) — The engine-systems testing checklist includes "Verify iBooster standby current within spec (ignition OFF)" but no standby-current spec value is documented anywhere (the brake-booster page does not state one). The test step cannot be completed as written.
  • WAIT-to-start lamp polarity: ECM Pin 35 active-low vs HDX input active-high (#150) — ECM Pin 35 (WAIT lamp, yellow) is active LOW (~0V when WAIT on, ~+12V off); the HDX indicator input is documented as active HIGH. If wired without resolving this, the cold-start indicator reads inverted — and the documented cold-start procedure depends entirely on watching the WAIT lamp.
  • Restomod Air HVAC integration — verify A/C request wiring to PMU In 9 + blower draw (#146) — The factory TJ HVAC is replaced by a custom Restomod Air electronic HVAC kit (ordered, owner-confirmed 2026-06-11) — this resolves the original "no A/C request source post-PCM-delete" gap. Restomod Air kits are fully electronic (servo-driven doors, no vacuum), and the control head generates the A/C request: compressor-engage output (12V) → trinary pressure switch (30/406 psi cutouts) → PMU In 9. PMU logic then drives OUT17 → compressor clutch.
  • AMOT 4261M 2.8″ intake air-path connection OD / reducer coupler to 2.125″ turbo inlet (#129) — The 4261M02 is a wafer butterfly valve that sleeves into a 2.8″ (71 mm) nominal intake duct; the AMOT datasheet (4261M_Air_Shutoff_Valve_0119rev2) publishes only nominal size (71 mm), bore (61 mm / 2.4″), and overall envelope — not the air-path spigot/wafer OD or clamp interface. The NPT thread in part number 4261M02A027-AA (actuator code 27) is the pneumatic control port, not the air path.
  • Grid Heater Current (#42) — Design value 80A - verify via element resistance measurement during installation (~0.15 ohm @ 12V).

Build Tasks

  • Determine GPS antenna mounting location (dash top vs windshield)
  • Determine if using SEN-15-1 temp probe with GPS-50-2 or separate BIM-17-2