The fuel injection system is at the heart of any diesel engine

A significant component of the system is the engine’s injectors and the computers that run them.
With increased demand on fuel efficiency and emissions regulations, much research has gone into the design of not only the injectors themselves but the Engine Control Units that operate them.
Injectronics says its team of dedicated technicians has identified a common issue with these systems, stating that a fuel injector can fail for a variety of reasons, including fuel contamination, faulty wiring or age.
When an injector fails, it can often lead to other issues if not fixed quickly and can, as a result, damage the ECM.

N14 Celect
Injectronics explains that the N14 Celect relies on electronically controlled, camshaft driven unit injectors. In the system, the camshaft provides final fuel pressure in each individual fuel injector, but the injectors utilise electronic solenoids that are actuated by the ECM. The result is greater timing, pulse width and pressure control. For 1997 Cummins introduced the N14 ‘Celect Plus,’ which primarily features a more sophisticated ECM and injection management system.
Injectronics says it has seen many of these units fail due to many and various causes, the most common being due to liquid/oil contamination. It explains this is usually caused by a leaking valve cover where the injector wires pass through. Engine oil runs down the wiring loom into the ECM connector and creates an electrical short to various components and this, in turn, causes multiple faults to be present. 
Other causes may be related to capacitor damage due to the age of these ECMs, internal shorts due to brittle wiring looms, and large amounts of corrosion.

Caterpillar 3126
The Caterpillar (CAT) 3126 engines produced by Cat from the mid-90s were used in a variety of different applications. The engine runs a 70 pin Engine Control Unit (ECU). Used by CAT in industrial equipment like wheel loaders/dozers/graders/excavators and compactors, this engine was also picked up by companies like Freightliner, Ford and Western Star in the US. This engine can also be found in the ‘Bushmaster’ vehicle built for the Australian Army, Freightliner and Kenworth in Australia.
With the introduction of the 3126B engine in 1998, we saw the introduction of Hydraulic Electronic Unit Injector system (HEUI), a fully electronically controlled injector system. Injectronics says it has come across a common issue with the ECU that runs this system, the fault being the vehicle will not start or is hard to start with no check engine light on the dash.

Temic ML-PLD
The Temic ML-PLD control unit is fitted to a large number of heavy-duty vehicles including Mercedes Benz Actros, Atego and Vario. Injectronics says it has been presented with many of these units having a number of common issues including:
• No power to injectors
• Running rough
• Dropping cylinders when warm
• No start
• One injector bank not functioning
• Fault code 4906 – “The feedback of the second-row plunger pump is short on the weight.”

Injectronics invites you to contact its team via or 1300 30 80 60 for assistance if you have any problems with heavy duty electronic or mechatronic modules.