CONSTANT READER

I was interested to read Duncan Mclachlan’s letter about diagnostics readers in Diagnostics Doctor (‘Fault code reader’, CM, April 2018), because I was in a similar situation when I bought my 2001 Mercedesbenz E320 CDI estate last year. Like you, I was wary of some devices available, with tales of dodgy or ‘cracked’ software and incompatibility with modern laptops. That the hardware might be some kind of copy or clone of an older genuinely-branded item was also of concern.

I was, however, impressed by the claims of MAXIECU software and the associated MPM-COM interface, which I bought from Scantool Direct, together with a dedicated 38-pin OBDII cable – this has data lines for more than just the engine ECU, unlike some other adaptor cables. The interface connects via USB, although a Bluetooth version is also available. Both the interface driver and the software work fine with Windows 10 and, as far as I am aware, the system allows me to read every ECU on the car.

A few weeks after I bought the reader, the car displayed multiple warning messages and lights for ABS, ESP and BAS. Connecting the interface and running the software pointed me in the direction of the brake-light switch – correctly, it seems, since I had no further trouble after replacing that item. An issue I noticed when I first bought the car was that kickdown only worked intermittently. I could see in the car’s service history that a previous owner had asked for this issue to be investigated, though there was no indication of the outcome. Checking the gearbox ECU revealed no fault codes, while the engine ECU flagged up an issue with the MAF sensor. Since fitting a new MAF sensor, kickdown has worked without fail.

I am fairly confident that the MAXIECU has already more than saved me its £136 cost. I note from Scantool Direct’s website that the price is now £145 for the USB interface with a Mercedes software license and 38-pin adapter. Spending £409 would add Bluetooth connectivity and software licenses for a wide range of vehicle makes.