MoTeC Global Forum

Hello there

We are facing a recurring issue with the Motec ECU. While running with the Motec ECU, all of sudden the engine stops working and the ECU is not detected.
We have got the ECUs repaired from Motec but the ECU again stopped working in the same way after few hours of stable operation.

Same issue was observed with GPR diesel as well.

Please suggest what could be the underlying problem.

Hi,

Can you please supply the serial number so that I can investigate this thanks.

Dear Sir,

for GPRDI, the Sr. No: 13142: 19458

for GPR Diesel: 13142: 11007

I have attached the photo's of both of the ECU.

Dhananjay
dhanu@iitk.ac.in

Hi,

I have spoken to the repair team and the issues that have been seen with these M1's is that the reverse polarity protection keeps being triggered. This is caused by positive voltage being applied to the Ground pins on the M1. You need to check your wiring and procedures to ensure that you are not feeding Battery Positive into the ECU grounds.

Hi Stephen,
Thanks for the reply. However with the same wiring this ECU was running for more than a year continously. Also, we checked all the wiring, when repaired ECU came back from Australia and it simply didn't work while engine is loading. The same problem occurrs with both the ECU (which have been repaired after feeding the negative with positive by mistake). This happened despite an external reverse polarity protection was employed!!!

We were instructed via India support team to use the charger while engine is in operation with ECU. We were testing the GPR-Diesel with the charger on, however the same issue persist.

Its important to mention here that....We have been using GPR-diesel in diffrent engines without the charger since long for many of our projects. The ECUs which have never been repaired...are working fine the same way.

So, kindly check...what could be the reason for the issue surfacing repeatedly for the Repaire ECUs only.

Could you please, let me know the reason for frequent failure? Thanks

Over voltage can cause the same issue as reverse polarity.

If you kill the power to the engine while is is running, the alternator no longer has a reference voltage and will happily generate a very high voltage.

I would like to use seperate fuse in between battery and ECU. What are the recommended Fuse Ampere rating for this ECU.

Hi,

I would put a current clamp on the feed into the M1 and see what current draw it has under load, and then size the fuse based off of that reading.

Hi Stephen, Thanks for your quick reply in this regard. Could you help me to understand one new issue while using the Motec M400 (Error Inj Max Duty).

While running the single-cylinder GDI research engine via M400 ECU, I am facing an abrupt injection end while engine operation, and showing the error "Inj Max Duty", on decreasing the pulse width on main fuel table, which is quite absurd. I have checked the fuel pressure and also with the new injector of the same specification. I have been operating at those values (pulse widths) earlier without any issues, but suddenly it is causing problems now. Kindly help what could be the reasons for this behavior.

Thnx