Section 2: Engine Systems¶

Engine bay systems and critical vehicle subsystems required for safe vehicle operation.

Contents¶

• 2.1 Starter System - Cummins R2.8 starter motor, solenoid, wiring, and control circuit
• 2.2 Brake Booster - Bosch iBooster Gen 2 electric brake booster system
• 2.3 HVAC System - Climate control, blower motor, and heater core circuits
• 2.4 Wiper System - Ron Francis WS-51C electronic wiper controller
• 2.5 Horn System - PIAA twin-tone horn with relay control
• 2.6 Radiator Fan - Electric radiator cooling fan system
• 2.7 Grid Heater - Cummins R2.8 cold-start grid heater relay and control
• 2.8 Fuel System - Lift pump control circuit (replaces factory PDC/PCM logic)
• 2.11 Runaway Protection - Mishimoto catch can + AMOT 4261M manual air shutoff

System Overview¶

Engine bay systems are powered primarily from the START battery via PMU24 programmable power distribution (see PMU). The PMU provides intelligent power management with ignition-triggered circuits, overcurrent protection, and diagnostic capabilities.

Critical safety systems (brake booster, starter) have direct battery connections for reliability.

Related Documentation¶

• PMU Power Distribution - Engine bay power distribution and control
• BODY PDU - Cabin convenience power distribution
• SafetyHub - High-current accessory fuse panel