During the SELECT-A-MAP ECU development we discovered that the level of control it gave and the detailed fuel injection information it provided had tremendous diagnostic potential:

  • DPF FilterInstallation of the SELECT-A-MAP ECU, with a high power map, can identify partially blocked DPFs, long before the vehicle’s ECU logs any errors or activates ‘limp’ mode. The test can be carried out simply by increasing the fueling (and consequently the exhaust gas volume) from the hand control. If this results in an EML or ‘limp’ mode activation, a partial DPF blockage may be present. 
  • When used with a scan tool to assist with forced regeneration, we found that increasing the amount of fuel raised the DPF core temperature and accelerated the forced cleaning process. 
  • During the forced regeneration procedure, while increasing fueling, if the core temperature should decrease rather than increase, it indicates that exhaust gasses may be leaking past the EGR valve, starving the DPF of oxygen (the core temperature reduces because there is insufficient oxygen to support the combustion of the extra fuel).
  • Following regeneration, if a high power map is selected during road testing, exhaust gas volume and temperature are increased, resulting in further passive cleaning of the DPF and also the full exhaust system. 
  • Select-A-Map ECU Internal View

    A particularly useful feature for technicians who are familiar with oscilloscopes, is the ability to monitor injector current flow waveforms directly from test-points on the Select-A-Map circuit board. These are provided at 3 different stages of the signal processing: A ‘raw’ sensor input that can be used to verify correct injector current, an amplified (maximised to 5v pk-pk) signal that can be used to examine the injector current flow waveform in detail and a processed square wave representation of injection pulses that can be used for oscilloscope triggering and accurate measurement of injection durations.


  • Installer Hand ControlThe installer handset can display engine load value data that is directly related to fuel rail pressure and injection duration. This can be used as a comparative diagnostic feature to check the load values of the engine under test against known, good values. There is also a live acceleration data value that is useful for assessing not only the smooth running of an engine but also its acceleration rate. Again, this can be used to compare values of the engine under test with known values of similar engines to assist in diagnosing induction faults, mechanical faults and exhaust flow faults.
  • Real time fuel rail pressure data displayed in Volts, and assumed pressure in BAR, can be used to assess pump condition and fuel line pressure decay. Due to the fast refresh rates of the displayed data, it is possible detect problems such as injector leak-off. 
  • Because the unit can be temporally and quickly fitted to a vehicle, it can be used as a selling tool to demonstrate to customers the performance upgrade potential of their own vehicle, whether they are considering a remap, tuning box or SELECT-A-MAP installation.

More diagnostic features are planned in future firmware upgrades.

Firmware upgrades are provided free* for 12 months after the purchase date.


* Select-A-Map units must be returned to CRD Technology for upgrades. Upgrades are free for the first 12 months but the customer is responsible for insurance and postal charges both ways.