5.6 Keyless Ignition System¶
Push-button ignition for the Cummins R2.8 + 8HP70 build. Replaces the factory keyswitch entirely. Self-contained Digital Guard Dawg PBS-I handles RFID immobilizer, brake interlock, and ACC/IGN/START sequencing internally. On a cold start the driver waits for the Cummins WAIT-to-Start lamp to extinguish before cranking — Digital Guard Dawg's documented diesel start procedure. PMU is not involved.
Architecture¶
Module: Digital Guard Dawg PBS-I (Intelligent Push Button Start)
Type: Self-contained RFID push-button start/stop; onboard 60A relays (IGN, START, ACC1, ACC2)
Mounting: On the Dakota Digital HDPE panel under the dash, co-located with the HDX control module (vendor mandate: cabin only, never engine bay)
Product Page: Digital Guard Dawg PBS-I
Install Manual: PBS-I Manual PDF
Components¶
Digital Guard Dawg PBS-I¶
| Specification | Value |
|---|---|
| Type | RFID push-button start, self-contained |
| Onboard Relays | 4× 60A1 (IGN, START, ACC1 drops during crank, ACC2 stays on during crank) |
| Inrush Capacity | 300A1 |
| Supply Voltage | 12V DC |
| Detection Range | ~10 ft (iTag fob) |
| Auto-arm | 60 sec after fob leaves range |
| Module Dimensions | ~5.5" × 3" × 1.25" |
| Wiring | Heavy-duty Molex high-current connectors, 12 GA bus wiring |
| Mounting | Dakota Digital HDPE panel, under dash — co-located with the HDX control module (panel detailed in the HDX Control plan). Vendor mandate: cabin only, never engine bay |
| Kit Contents | ICM + 2 iTag fobs + Start Button (36" pre-wired harness) + Programming Button + Bypass Card + 4-digit PIN |
Cole Hersee 24213 Solenoid¶
Unchanged from existing starter design. See Starter System.
Daily Start Sequence¶
Warm engine (no preheat cycle):
- Approach vehicle — iTag fob in pocket — Start Button LED illuminates
- Press brake pedal — Start Button LED begins flashing
- Press and hold Start Button — starter cranks immediately, release on engine start
Cold engine (grid heater active):
- Approach — fob recognized — Start Button LED illuminates
- Press Start Button twice (no brake) → IGN energizes → ECM powers up → grid heater runs → WAIT-to-Start lamp illuminates
- Wait ~3-5 seconds (per Grid Heater) for the WAIT-to-Start lamp to extinguish
- Press brake + press and hold Start Button → starter cranks
- Release on engine start
Shut off: Press brake + press and hold Start Button for 2 seconds.
Accessory-only mode (e.g., radio without engine): press button once without brake — ACC2 energizes. Second press adds ACC1 + IGN.
Emergency bypass (lost or damaged fob): Use Programming Button + 4-digit PIN from the Bypass Card stored in wallet. See PBS-I Manual.
Wiring¶
PBS-I Power Harness (6 wires)¶
| Wire | Function | Source | Destination | Notes |
|---|---|---|---|---|
| RED | +12V Battery | Critical Cabin PDU (CONSTANT) | PBS-I module | 14 AWG; ~50 mA standby (⚠️ TBD #84) |
| BLACK | Chassis Ground | Cabin ground bus | PBS-I module | 14 AWG |
| PINK | 1st Ignition Out (60A) | PBS-I module | Ignition signal bus bar (cabin), Stud 1 | Does NOT drop during crank; bus bar Stud 2 outbounds to ECM Pin 41 via 5A inline fuse3 |
| PURPLE | Starter Out (60A) | PBS-I module | Firewall Pin 15 → Cole Hersee 24213 coil+ | Cranks while button held |
| PINK/BLK | Accessory 1 (60A) | PBS-I module | [Reserve] | Drops during crank |
| BROWN | Accessory 2 (60A) | PBS-I module | [Reserve] | Stays on during crank |
PBS-I Accessory Harness (2 wires used)¶
| Wire | Function | Source | Destination | Notes |
|---|---|---|---|---|
| BROWN | Brake (+) input | Stop-lamp switch cold side | PBS-I Brake input | T-tap shared with PMU In 2 and Turbolamik brake input |
| PURPLE | Ground upon Disarm | PBS-I module | [Reserve] | Active-low fob-present signal; available for future use |
Start and Programming Buttons¶
| Connector | Connection | Notes |
|---|---|---|
| Start Button | Pre-wired 36" harness → PBS-I side port | Mounts at the factory keyswitch location on the dash (within the 36" harness reach of the panel); included in kit |
| Programming Button | Pre-wired harness → PBS-I side port | Stash under dash or in trunk; needed only for fob-learn and emergency bypass PIN entry |
Firewall Crossings¶
Two PBS-I outputs need to cross the firewall from cabin (PBS-I location) to engine bay:
| Signal | Direction | Approximate Current | Notes |
|---|---|---|---|
| Ignition signal (outbound from cabin bus bar) | Cabin → EB (HDP24 Pin 12) | ~5A typical (ECM + PMU Pin 7) | 14 AWG; feeds ECM Pin 41 (black, via 5A inline fuse3) and PMU Pin 7 |
| PURPLE START | Cabin → EB (HDP24 Pin 15) | ~0.69A (Cole Hersee coil)2 | 16 AWG sufficient; drives Cole Hersee 24213 coil+ during crank only |
See Firewall Ingress for pin assignments.
Why Not the Engine-Running Lockout or P/N Interlock Relay?¶
Earlier iterations of this design included a discrete engine-running lockout relay and a P/N interlock relay in series with the starter coil. Both were removed in favor of simpler, layered protection:
- Brake interlock is built into PBS-I (Accessory Harness Brake input).
- Engine-running protection relies on the starter's Bendix overrunning clutch plus the deliberate brake + button-hold required to crank — accidental restart of a running engine takes two-handed misuse.
- P/N interlock is provided by the 8HP70 + Turbolamik: the transmission can't leave Park without brake pressed, and the vehicle is always in Park at start time. The Turbolamik P/N aux output can inhibit the start signal in a future phase if needed (documented, unused today).
Diesel Runaway Note¶
Normal engine shutdown (press brake + 2 sec button hold) drops PBS-I's PINK IGN output, cutting ECM power. However, ECM-only kill does not stop a runaway sustained by oil or hydrocarbon vapor. Independent mechanical protection is provided by the Mishimoto catch can (prevention) plus the AMOT 4261M air shutoff valve with dash-mounted manual cable (termination). See Diesel Runaway Protection.
Outstanding Items¶
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Related Documentation¶
- Starter System - Cole Hersee 24213 and PBS-I PURPLE START → coil chain
- Ignition Signal Distribution - PBS-I PINK IGN feeds the bus bar
- HDX Control - ECM Pin 35 WAIT/EX signal (dash display)
- Grid Heater System - R2.8 grid heater duty cycle (3-5 sec typical)
- Firewall Ingress - PBS-I pin assignments
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Onboard relay ratings (4× 60A), 300A inrush capacity, and kit contents per the Digital Guard Dawg PBS-I install manual (PBS-I Manual PDF) and product page (Digital Guard Dawg PBS-I). ↩↩
-
Cole Hersee 24213 coil draw ~0.69A (17.5 Ω @ 12V) per the Littelfuse datasheet — see the
[^ch-24213]footnote in Starter System. Supersedes the earlier unsourced "~1.6A" figure that appeared in pre-merge drafts. ↩ -
Confirmed. Cummins Repower R2.8 CM2220 R101B Installation Guide, Bulletin 5504137 (Jan 2018), §2 Wiring Harness (pp. 2-19/2-20): the keyswitch feed to the ECM is Pink, ECM pin 41, with a 5 amp inline fuse (Figure 2, item 3: "Keyswitch – pink, 5 amp inline fuse"). The guide requires this "pink 5 amp wire … provide a minimum of 12 volts in the run position and during engine cranking." Supersedes the unverified "document 0042728" cited in pre-merge drafts. ↩↩