478-7933 4787933 Engine Control Module ECM for Caterpillar C15 C18 AD45 R2900G Loaders
478-7933 ECM — direct replacement for Caterpillar AD45, R2900G and C15 / C18 engines.
- Interchangeability: Replaces 478-7933 / 4787933. Existing bracket and harness connectors, no rewiring.
- Application: Fits for Caterpillar AD22–AD55 trucks, R1700G / R2900 / R3000H, MD6290, 627G, 637G, 586C.
- Programming Required: Ships unflashed — must be configured to your engine serial number by a workshop.
- Check Your Variant: Underground machines are often re-engined — order from the ECM label, not the fleet record.
$1,399.00
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Bench-Tested - Every unit powered up and function-tested before dispatch.
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6-Month Warranty - From delivery, against defects in materials and workmanship.
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30-Day Returns - Unused items in original packaging. RMA required.
Product Details
478-7933 (4787933) engine control module — a direct-replacement ECM for Caterpillar underground haul trucks in the AD22 to AD55 range, R1700G / R2900 / R3000H load haul dump loaders, MD5075 and MD6290 drills, 6015 / 6018 hydraulic shovels and C7 through C18 industrial and petroleum engine builds.
This is the underground and hard-rock specification of the family, and it is checked accordingly. Each unit is opened and inspected under magnification, the board is cleaned, connector shells and housing seals are examined for the moisture and dust ingress that underground work drives into everything, and continuity through the header pins is verified. The module is then run on a bench harness and function-tested against factory-specified operating parameters before it is packed.
- The widest engine coverage in this family: C7, C9, C11, C15 and C18 industrial and petroleum builds under a single reference.
- Direct replacement — existing bracket, existing harness connectors, no machine-side modification required.
- Built to restore original operating parameters, with engine protection and emissions strategies left as the factory defined them.
- Connector seals, housing gasket faces and header pin continuity checked specifically for underground duty, where water and rock dust are the main killers of control modules.
- Suits mixed underground fleets where AD-series trucks, R-series loaders and MD-series drills share one spares holding.
- Listed under both 478-7933 and 4787933. The unit ships bare and must be flashed — see the notice below.
Programming Required — No Engine Software Is Pre-Loaded
The module contains no application software for your engine and will not start it until a workshop with dealer-level service tooling has flashed and configured it. Underground fleets often run several arrangements of the same engine, so accurate details matter here. Please send:
- Engine Serial Number (ESN) and Vehicle Identification Number (VIN)
- Clear photographs of the ECM currently fitted, with every number on the label readable
- A photograph of the engine data plate showing the arrangement number
- Machine model and serial prefix — for example AD45B, R2900G or MD6290
Removal and refitting should be done by an experienced technician. Isolate the batteries and the machine at its main disconnect before touching the connectors. On underground machines, blow the connector area clean and dry it before unplugging, so accumulated dust and water are not pulled into the open connector shell during the swap.
Fitment & OEM Interchange
Caterpillar and CAT machine model designations appear below only to identify the equipment this aftermarket module is built to fit. The OEM interchange numbers listed are cross-reference data for identification purposes and do not imply that this part is made, supplied or endorsed by the trademark holder.
Part Number Cross-Reference
| Reference Number | Format / Role | Notes |
|---|---|---|
| 478-7933 | Primary reference, hyphenated | The form used in service literature. |
| 4787933 | Same reference, no hyphen | How the number is normally entered into stores systems. |
| 478 7933 | Space-separated variant | Occasionally seen on requisitions and job cards. |
Related Reference Numbers — Same Replacement Family
The reference numbers below sit in the same replacement family and turn up on machines with overlapping application lists. They are not automatically interchangeable — coverage varies by build date and engine arrangement, so read the label on the module currently fitted, or send us a photo of it, before you order.
| Reference Number | Typical Coverage Difference |
|---|---|
| 226-7475 / 2267475 | Narrower list centred on 365C / 385C excavators, 627G / 637 scrapers and the 586C. |
| 20R-8182 / 20R8182 | Remanufactured-numbered unit covering the scraper, 586C and AD30 side of this list. |
Application Chart — Fits For Caterpillar
| Machine / Engine Category | Models |
|---|---|
| Engine – Machine | C9 |
| Hydraulic Shovel | 6015, 6015 FS, 6018 |
| Industrial Engine | C7, C9, C11, C15, C18 |
| Load Haul Dump | R1700G, R2900, R2900G, R3000H |
| Mobile Hyd Power Unit | TH43-C18 |
| Petroleum Engine | C7, C9, C18 |
| Petroleum Package | CX31-C15I, CX35-P800, TH31-C9P |
| Rotary / Track Drills | MD5075, MD5075C, MD6290 |
| Site Prep Tractor | 586C |
| Underground Art Truck | AD22, AD30, AD45, AD45B, AD55 |
| Wheel Scraper | 627G, 637D, 637E, 637G |
| Wheel Tractor | 627G, 637G |
Before You Order
Underground machines are rebuilt and re-engined more often than surface equipment, so the engine in the machine today is not always the one it left the factory with. Work from the label on the module you are removing and the engine data plate, not the fleet number or the as-built machine specification. Send us both photos and we will confirm the reference before you order.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Name | Electronic Engine Control Unit — ECM / ECU Module |
| Reference Numbers | 478-7933, 4787933 |
| Condition | ⚠️ TO CONFIRM — condition was not supplied in the source data. Set this field before publishing. |
| Installation Method | Direct replacement — mounts to the existing bracket and mates with the existing machine harness |
| Programming | Required — flashing and configuration with engine-specific software by a workshop with dealer-level tooling |
| System Voltage | 24V nominal on the machines listed — application dependent, confirm on the data plate |
| Housing Material | Sealed die-cast aluminium case with integral heat-sink face |
| Connectors | Sealed multi-pin machine harness connectors — pin count is application dependent, match against the module being replaced |
| Circuit Protection | Reverse-polarity and transient suppression to factory-specified design; no protection features removed or bypassed |
| Testing | Powered up and function-tested on a bench harness before dispatch |
| Warranty | 6 months from delivery, against defects in materials and workmanship |
| Package Contents | 1 × engine control module. Brackets, harness, gaskets and software licences are not included. |
This module is supplied to restore factory-specified performance and original operating parameters only. Emissions-related calibration and engine protection strategies are left exactly as the factory defined them; we do not supply, alter or support any change to emissions control functions.
Common Failure Symptoms
Underground trucks, LHD loaders and drills put control modules through heat, water and vibration at the same time, and the failure pattern reflects that. These are the symptoms that most often end up being an ECM fault on this equipment group.
| Symptom | What It Usually Points To |
|---|---|
| Truck or loader cranks well but will not fire, with no injector activity at all | The injector driver bank or the internal supply feeding it has failed. |
| Engine starts underground but dies within minutes near a hot heading | A thermally intermittent internal fault that only appears as ambient temperature climbs. |
| Machine derates to a crawl part way through a shift with no fuel or air restriction found | The module has fallen back to a default limp strategy after an internal fault. |
| Green corrosion or water droplets inside the ECM connector shell | Ingress has reached the module inputs; the harness seals almost always need attention too. |
| Service tool will not connect to the engine controller although the display works | Data link transceiver failure inside the module, or a lost power or ground supply. |
| A cluster of unrelated sensor codes logged at the same moment | Collapse of the regulated sensor supply generated inside the module. |
| Drill or LHD loses throttle control intermittently while tramming | Vibration-related cracking at the connector headers on the module board. |
| ECM fault codes that reappear immediately after the memory is cleared | Corrupted internal memory or a failing configuration store. |
Rule Out The Cheap Causes First
Underground, the harness fails far more often than the module. Before ordering, check battery condition and the charging circuit, clean and torque the ground straps, pressure-wash nothing near an open connector, and inspect the loom for chafe against the frame and for water tracking down into the ECM plugs. If the module has clean supply and ground yet still will not communicate, then the module is the likely fault.
Shipping & Quality Guarantee
- Dispatch: orders are dispatched in 1–3 business days after the fitment details are confirmed.
- Free express delivery: DHL / FedEx / UPS, 3–8 business days door to door.
- Tracking: a tracking number is issued within 24–48 hours of dispatch.
- Bench-tested: every unit is powered up and function-tested before it leaves the workshop.
- 6-month warranty from delivery, against defects in materials and workmanship.
- 30-day returns on unused items in their original packaging; an RMA number is required before shipping anything back.
- Protective packaging: anti-static bag, foam-lined carton, connector caps fitted to keep the pins clean in transit.
- Technical support: send us your data plate photos and we will confirm the reference number before and after the sale.
Shipping & Customs Notice
The amount charged covers the product and shipping only. Import duties, VAT, GST, customs clearance charges and any other local taxes are not included and remain the responsibility of the buyer. Please check your own country’s import rules before ordering.
Caterpillar®, CAT® and all machine and engine model designations are the registered trademarks of their respective owners. We are an independent supplier of aftermarket replacement parts and have no affiliation with, sponsorship from or authorisation by the trademark holder. Reference numbers including 478-7933 / 4787933 are quoted purely as OEM cross-reference data to help you identify the correct fitment.
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