2018 Freightliner Cascadia Power Distribution
The 2018 Freightliner Cascadia operates using the OBD 16 system. Battery power in the Cascadia is protected by fuses located at standard and optional locations. The primary power distribution center for the vehicle is the Mega Fuse Junction Block (MFJB).
At the MFJB, battery power is directed to various components including the alternator, SAM Cab, SAM Chassis, powertrain PDM, and optional loads. Optional components such as the in-cab auxiliary PDM and chassis PDM are also connected to the MFJB.
Additionally, battery power from the MFJB can be routed to an inverter and a trailer cable. The Cascadia is equipped with a load disconnect switch that isolates the MFJB from the batteries.
However, it’s important to note that battery cables connecting the starter and emergency power circuits remain active even when the load disconnect switch is engaged.
Details of Freightliner Cascadia Power Distribution Module.
There are total 6 (six) no of Power Distribution Module in 2018 Cascadia:
- Powertrain PDM : The powertrain PDM provides battery and ignition power to the engine, aftertreatment device, and transmission, in addition to optional powertrain related circuits. The powertrain PDM is mounted above the driver-side inner fender.
- In-Cab Auxiliary PDM : The optional in-cab auxiliary PDM is installed in one of two locations. On 113 BBC vehicles, the PDM is mounted on an HVAC duct in the dash, and accessed by removing the auxiliary dash panel. On 125 BBC vehicles, the PDM is mounted on the engine tunnel inside the cab next to the central gateway. Battery power to the in-cab auxiliary PDM is protected by a 30-amp inline fuse located near the SAM chassis in the engine compartment.
- Chassis PDM : The optional chassis PDM is mounted on a bracket forward of the between-rail battery box, or inside the between-rail battery box. When mounted outside the battery box, there may be additional relays and an inline fuse on the lower side of the mounting bracket.
- SAM Cab : The SAM cab contains the electronic controls and the fuses and relays for cab electrical systems. It is located in the passenger side of the dash and accessed by removing the glove compartment. The shields covering the SAM cab must be re-installed after the SAM is accessed.
- SAM Chassis : The SAM chassis contains the electronic controls and the fuses and relays for most of the chassis electrical system. It is located on the driver side of the front wall in the engine compartment. The cover over the SAM chassis fuse and relay area must be completely latched into place after they are accessed.
- Powernet Distribution Box : The Powernet Distribution Box (PNDB), installed on EPA10 vehicles, provides 4 circuits that are always powered, and three high amperage circuits that are switched on and off with the optional cab load disconnect switch (CLDS). A flashing LED on the PNDB or the CLDS indicates an error with the system.
2018 Freightliner Cascadia PDM, Fuse & Relay Location
1. Powertrain PDM
The powertrain power distribution module (PDM) is mounted in the engine compartment next to the left front inner fender.
2. In-Cab Auxiliary PDM
On 113 BBC vehicles, the in cab auxiliary PDM is located on the HVAC duct behind the center dash panel and is accessed by removing the auxiliary dash panel. On 125 BBC vehicles, the PDM is mounted on the engine tunnel inside the cab, next to the central gateway.
3. Trailer (Chassis) PDM
The chassis PDM is either mounted on a bracket forward of the between-rail battery box, or inside the between-rail battery box.
4. SAM Cab
5. SAM Chassis
The SAM chassis PDM fuse and relay in the 2018 Freightliner can be accessed from the engine side cabin, specifically located in the inner fender of the driver’s side. The connector or access point for these components is reachable from the driver’s cabin.
5. Powernet Distribution Box
The powernet distribution box (PNDB) is located on the cab front wall, above the main ground junction block.
2018 Freightliner Cascadia Fuse Box Diagram
1. Powertrain PDM
2018 Freightliner Cascadia Powertrain PDM Fuse Box Diagram
2018 Freightliner Cascadia Powertrain PDM Fuse Box Details
| No | Fuse and Relay Details | Rating |
| F1 | ECM/MCM, BAT | 30 A |
| F2 | CPC, BAT | 10 A |
| F3 | Spare | — |
| F4 | SAM CHAS, EMG PWR, BAT | 20 A |
| F5 | Autolube | 20 A |
| F6 | Spare | — |
| F7 | Spare | — |
| F8 | PTO/IGN | 10 A |
| F9 | Spare | — |
| F10 | CPC/MCM/ACM, IGN | 5 A |
| F11 | Optimized Idle Alarm, IGN | 10 A |
| F12 | Autolube | 5 A |
| F13 | SPARE | — |
| F14 | Spare | — |
| F15 | Spare | — |
| R1 | Ignition | 30/40 A |
| R3 | Spare | 10/20 A |
| R4 | PTO # 1 | 10/20 A |
| R5 | PTO # 2 | 10/20 A |
| R6 | Spare | 10/20 A |
| R7 | Autolube | 20 A |
| R8 | Spare | 20 A |
| R9 | Spare | 20 A |
| R10 | Spare | 20 A |
| R11 | Spare | 20 A |
| R12 | Spare | 20 A |
2. In-Cab Auxiliary PDM
2018 Freightliner Cascadia In-Cab Auxiliary PDM Fuse Box Diagram
2018 Freightliner Cascadia In-Cab Auxiliary PDM Fuse Box Details
| No | Fuse and Relay Details | Rating |
| F1 | ECM/MCM, BAT | 30 A |
| F2 | Spare | — |
| F3 | TCU, BAT | 10 A |
| F4 | SPARE | — |
| F5 | Spare | — |
| F6 | DEF Line Heater, BAT | 20 A |
| F7 | TCU, IGN | — |
| F8 | Spare | — |
| F9 | ENG / SCR NOX Sensor, IGN | 20 A |
| F10 | ECM, IGN | 5 A |
| F11 | Electric FAN, IGN | 10 A |
| F12 | DCU, IGN | 5 A |
| F13 | SPARE | — |
| F14 | Spare | — |
| F15 | Spare | — |
| R1 | PTO #2 | Mini |
| R2 | Ignition | 70 A |
| R3 | Auto Neutral | Micro |
| R4 | DEF Line Heater | Micro |
| R5 | PTO # 1 | Micro |
| R6 | Electric Fan | Micro |
| R7 | Neutral Interlock | Micro |
| R8 | Spare | — |
3. Trailer PDM Fuse Box
2018 Freightliner Cascadia Trailer PDM Fuse Box Diagram
4. SAM Chassis Fuse Box
2018 Freightliner Cascadia SAM Chassis PDM Fuse Box Diagram
2018 Freightliner Cascadia SAM Chassis PDM Fuse Box Details
| No | Fuse and Relay Details |
| SAM Chassis Relays | |
| R1 | H2O SEP HEAT, IGN |
| R2 | TRLR TRN L |
| R3 | ABS/WIF/CAMERA, IGN |
| R4 | TRLR TRN R |
| R5 | TRLR MARKER |
| R6 | TRLR ABS, IGN |
| R7 | TRLR STOP LAMPS |
| R8 | TRLR POWER |
| R9 | TRLR TAIL LAMPS |
| SAM CHASSIS FUSE | |
| F1 | EAPU (20A) |
| F2 | H2O SEP HEAT (20A) |
| F3 | ABS—BAT1 (20A) |
| F4 | ABS—BAT2 (10A) |
| F5 | TRLR TRN L (20A) |
| F6 | ABS—IGN (15A) |
| F7 | WIF/CAMERA (10A) |
| F8 | TRLR TRN R (20A) |
| F9 | TRLR MKR (30A) |
| F10 | SAM RELAY COILS (5A) |
| F11 | TRLR ABS—IGN (30A) |
| F12 | TRLR STOP (30A) |
| F13 | TRLR TAIL (20A) |
| F14 | TRLR PWR (30A) |
5. SAM Cab Fuse Box
2018 Freightliner Cascadia SAM Cab PDM Fuse Box Diagram
2018 Freightliner Cascadia SAM Chassis PDM Fuse Box Details
| No | Fuse and Relay Details |
| SAM Cab Relays | |
| R1 | PWR FD SPARE 1 and 3, BAT |
| R2 | PWR FD SPARE 2 and 4, BAT |
| R3 | HEATED SEAT, IGN |
| R4 | DASH PWR RCPT 1 and 2, BAT |
| R5 | FLT MGM SYS and CB, BAT |
| R6 | PWR RCPT3 and STD HVAC, BAT |
| R7 | DRV INFO/GAUGE, IGN |
| R8 | ICU/VEHICLE SYS, IGN |
| R9 | AMPLIFIER PWR, ACC |
| R10 | MIRROR HEAT |
| R11 | PWR RCPT 6 / FRIG, BAT |
| R12 | PWR RCPT 5, BAT |
| R13 | CAB LIGHTING, BAT |
| R14 | PWR RCPT4/CIR FAN/LAMP, BAT |
| R15 | PWR WINDOW, ACC |
| SAM Cab FUSE | |
| F1 | PWR FD SPARE 1 and 3 (30A) |
| F2 | CAB/SLPR HVAC CTRL/SHF PNL (15A) |
| F3 | PWR FD SPARE 2 and 4 (30A) |
| F4 | MSF (15A) |
| F5 | OBD J1939—BAT (10A) |
| F6 | DASH PWR RCPT 1 (15A) |
| F7 | DASH PWR RCPT 2 (15A) |
| F8 | PHONE/RADIO—BAT (15A) |
| F9 | AMPLIFIER PWR (20A) |
| F10 | CAB HVAC MTR (30A) |
| F11 | SLPR HVAC MTR (30A) |
| F12 | DR CTRL L (20A) |
| F13 | DR LOCK/SM CRUISE (20A) |
| F14 | FLT MGM SYS and CB (25A) |
| F15 | SLPR PWR RCPT 3 (20A) |
| F16 | STAND ALONE HVAC (7.5A) |
| F17 | SLPR PWR RCPT 4 (20A) |
| F18 | TELEMATICS/WARNING SYS (15A) |
| F19 | HEATED SEAT (20A) |
| F20 | CGW (2A) |
| F21 | AREA LIGHT (15A) |
| F22 | ICU—BAT (5A) |
| F23 | DR INF /GAUGE (15A) |
| F24 | ICU—IGN (10A) |
| F25 | DASH SPLICE PACK (7.5A) |
| F26 | SRS—AIRBAG (5A) |
| F27 | MIRROR HEAT L (10A) |
| F28 | MIRROR HEAT R (10A) |
| F29 | SAM RELAY COILS (3A) |
| F30 | PWR RCPT 6 / FRIG (20A) |
| F31 | SLPR PWR RCPT 5 (20A) |
| F32 | PWR FD SPARE 5 and 6 (25A) |
| F33 | SPOT LIGHT (20A) |
| F34 | BAGGAGE COMP LAMP (3A) |
| F35 | DOMELAMP CAB (15A) |
| F36 | AUX CIR FAN/RD LAMP (15A) |
| F37 | CLK/DRV INFO/CD/KEYLESS (15A) |
| F38 | DR CTRL R (20A) |
| F39 | PWR WINDOW R (15A) |
| F40 | PWR WINDOW L (15A) |
6. PNDB Fuse Box
2018 Freightliner Cascadia PNDB Fuse Box Diagram
2018 Freightliner Cascadia PNDB Fuse Box Details
| No | Fuse and Relay Details |
| PNDB ATC Fuse | |
| ATC-A | After treatment control module |
| ATC-B | Emergency Power |
| ATC-C | Radio and Clock |
| ATC-D | Alternator Remote Sense |
| PNDB MIDI FUSE | |
| MIDI-1 | Powertrain PDM |
| MIDI-2 | SAM Chassis |
| MIDI-3 | SAM Cab |
WARNING: The terminal and harness assignments for individual connectors may vary depending on the vehicle’s equipment level, model, and market. It is recommended to refer to the fuse box diagram provided at the back of the fuse box cover for accurate information.
