Tech Talk

Replace or repair? When time is money

Commercial vehicles are the backbone of the transport and logistics industry. They are designed to work long hours, hauling significant loads. When the vehicle is down for repairs, it is not earning its keep. In reality, this downtime is lost income.

Root-cause analysis is the process of identifying the cause of the failure so the fault will not return when repairs are completed. 

Electronic control units or modules (ECUs or ECMs) are a source of frustration for repair technicians because they frequently malfunction, show intermittent faults in unrelated systems and can fail due to problems external to the module. ECUs are key parts of almost every vehicle system and diagnosis is anything but straightforward.

Injectronics specialist technicians can offer insight into the cause of the original fault and advise of any necessary checks required to repair the failure.

Unitised power 

A unitised power system is where the engine mechanical and electronic control are developed as a package and can be utilised across a diverse range of heavy-transport and plant-equipment applications.

This makes the power unit very popular with chassis and plant manufacturers because wiring looms are kept short and the engine control module is bolted directly to the engine for simplicity and reduced production cost.

This design feature is unfortunately a double-edged sword because the features that make it so desirable for manufacturers are the same ones that can let the vehicle down.

Oil leaks from the valve cover can follow the wiring harness back to the ECM and permeate its sealing resins, breaking them down. When the valve cover is replaced and the engine is pressure-washed, moisture can enter the ECM, causing intermittent driveability faults and random diagnostic trouble codes (DTCs).

If the power unit is subjected to harsh vibration and/or repeat physical shock – such as worn engine mounts or when the engine is used in plant equipment with no suspension – the ECM circuit board or electronic componentry can fail. 

Again, in this instance, Injectronics can advise the technician what additional checks may be required to prevent repeat failure. 

If the ECM cannot be repaired due to extensive damage and a new replacement module is required, it must be programmed and often security linked with other modules. Unless performed correctly, issues can occur within seemingly unrelated systems.

In most cases when module failure occurs, Injectronics can repair the original unit without loss of critical calibration files.

Plug ‘n’ play convenience

In most cases when module failure occurs, Injectronics can repair the original unit without loss of critical calibration files – meaning only minor relearn procedures are required when the repaired ECM is refitted to the vehicle.

When repair is not possible, Injectronics can typically transfer the original files to a replacement module – a true plug ‘n’ play solution.

Cause and effect

A great example of this is identifying burnt areas on control boards. These can typically be traced back to sensor or actuator faults. Knowing which particular area was damaged means a specific circuit can be tested and repaired to avoid repeat failure.

The widespread use of ECMs in heavy commercial and plant equipment has made servicing this industry a major area of growth and resource allocation. 

800 and counting

Injectronics currently lists more than 800 different ECMs with an identified and proven repair procedure. The company is also particularly proud of its ‘First Unit’ department, which is constantly evaluating, decrypting and problem-solving new units to add to the database, which is why Injectronics encourages enquiries regarding units not listed on the website.

For more information, contact Injectronics on 1300 308 060, email or visit

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