By Joe Toup
There does not seem to be a lot of good sources out there for troubleshooting and diagnosing ECU problems with my Massimo Buck 400 (which is also a Bennche 400 & Cazador 400 only with different badging), so I thought I'd share some info that I found during my searches the past few days. I was trying to diagnose and repair a hard starting issue. Using the following info, I was able to figure it out. My ignition coil threw a 0351 code. I discovered how to read the codes without an OBDII code reader. The following procedures should help you check your fault codes and clear them if needed.
Fault Code Troubleshooting for Delphi MT05 ECM on the Massimo Buck 400, Bennche Bighorn 400, Bennche Cowboy 400, and Cazador 400
*NOTE: The MT05 ECU is not really OBD 2 compliant. It is much more similar to an OBDI system. I know this because I once converted a Suzuki Samurai from carburetor to a full on EFI system a while back and it had all of the same type of sensors as a Delphi EFI system. The MT05 ECU controls either 1 or 2 cylinder engines commonly found on Massimo, Bennche, and Cazador.
Much of the ECU info was found here:
https://netcult.ch/elmue/HUD ECU Hacker/Delphi MT05 Manual.pdf
Delphi EFI System Design
Delphi EFI employs 5 sensors to monitor engine performance.
1. Crankshaft Position Sensor
2. Coolant Temperature Sensor
3. Oxygen Sensor
4. Throttle Position Sensor
5. Manifold Air Pressure/Manifold Air Temperature (MAP/MAT) Sensor
Delphi EFI employs the following system components.
1. MT05 Engine Control Unit (ECU)
2. Fuel Pump
3. Multec 3.5 Fuel Injector
4. Idle Speed Control Valve (Idle Stepper Motor)
5. Multec Ignition Coil
6. Fuel Vapor Canister Purge Valve
Using the Digital Dashboard to Decipher EFI Trouble Codes
In addition to the diagnostic scan tools, you can use the engine warning light of the Siemens dashboard to diagnose EFI problems. The digital dashboard receives signals from the MT05 ECU, and the engine warning light will flash a diagnostic trouble code (DTC) if the ignition key is switched on/off for three cycles.
When you turn on the ignition, the engine warning light will illuminate, which indicates the EFI system is operational. After the engine is started, the engine warning light will extinguish if the EFI system is working properly. However, if the engine warning light remains illuminated, it indicates the EFI system is not working properly, and there is a system component failure.
Deciphering Diagnostic Trouble Codes
To read the diagnostic trouble code (DTC), open and close the ignition key three times in rapid succession, as follows: open/close—open/close—open. At this point the engine warning light will flash a DTC which indicates the fault in the EFI system. Refer to the attached fault code table to identify the corresponding problem.
The engine warning light will emit a sequence of flashing lights. If the light flashes 10 times, the translated number is 0. If the light flashes one time, the translated number is 1, et cetera. For example, if the MAP/MAT sensor is disconnected, or the connector is shorted to ground, the engine warning light will flash in the following manner (This is an example only).
The engine warning light will flash 10 times: The first number of the DTC is 0
After an interval of 1.2 seconds, the engine warning light will flash 1 time: The second number of the DTC is 1
After an interval of 1.2 seconds, the engine warning light will flash 10 times: The third number of the DTC is 0
After an interval of 1.2 seconds, the engine warning light will flash 7 times: The fourth number of the DTC is 7
The resulting DTC is P0107.
In my case, I had an ignition coil failure that threw a code. When I checked, it was in this sequence: 10, 3, 5, 1. The 10 represents a 0. So the actual code was 0351. I fixed a loose wire and rebooted my ECU using the procedures I detailed below.
If there are other fault codes, the engine warning light will flash the next code in 3.2 seconds after finishing P0107. After all existing fault codes are flashed, the engine warning light will repeat the fault codes, in sequence, until the ignition key is turned off.
To clear fault codes you need an OBDII Fault Code reader and a Delphi 6 pin connector adapter cable that you have to order from China and wait 8 weeks…or you can simply reboot the ECU using the instructions detailed below.
Rebooting the ECU
Perform the following steps to reboot the ECU.
1. Turn off the ignition for 15 seconds.
2. Turn the ignition on/off for 5 cycles. Make sure each cycle lasts about ½ second, verifying the start of the fuel pump for each cycle. If the fuel pump doesn't start during any cycle, begin the entire reboot procedure from the beginning.
3. Turn off the ignition for 15 seconds.
TPS (throttle position sensor) re-learn procedure after rebooting ECU.
This must be done after replacing the TPS or the ECU....and after rebooting an ECU! Source: ECU Hacker. Reworded slightly to make it a more sensible flow in my mind. 1. Turn idle screw one full turn clockwise before starting 2. Start engine, run at low idle until engine warms. Maybe a couple mins. 3. Idle should be above 1500 rpm. If it isn’t, turn it up to 1700 then shut engine off. Do another reboot of ECU. 4. Restart engine and let it stabilize at 1700 rpm. Then turn idle screen down to 1500 rpm and let it stabilize for a few seconds. Once it stabilizes, set to final recommended idle speed for your machine. The placard under your seat should show idles speed, valve adjustment, spark gap, etc. mine shows 1600 rpm.
5. Shit it down. Wait 10-15 second before restarting. Procedure is now complete. Final Notes:
I have included pictures of the OBDII connector and the Delphi 6 pin connector in case anyone wants to go buy your own and build a connector to use for an OBDII reader. You can do the same thing with code reading and resetting using your check engine light on your dash. But some folks want to do it with code readers.
Hope this helps some folks. I have been scratching my head until tonight on how to reset my fault codes. Then I discovered all of this on some motorcycle forums. The source for the diagrams is here:
https://netcult.ch/elmue/HUD ECU Hacker/
I am not a technician. I do not endorse any manufacturers. I am just an OCD driven old man that likes to work on my own crap. I have lots of time to figure things out. If you run into a problem that stumps you, give me a shout. I may be able to give you some ideas. Or maybe not. This system is essentially an OBDI and very simplistic. If you are methodical and patient, most problems can be figure out thru a process of elimination.
By Heidi Wilmoth
You will quickly see that I am new to this and don't quite know how to pose this question. I gave myself a Coleman 400 UTV for my 65th birthday a month ago."To Yaya: From Yaya" I've noticed a couple issues. First, as I drive around our acreage, sometimes it just putters, almost sounds like it's going to turn off. The other issue is the lights on the dashboard that correspond with forward, neutral and reverse don't match up to the actual gear. Sometimes it does but most of the time it doesn't. What I mean is that when I put it in forward to drive, the reverse light will be on the dashboard light. Sometimes it will be the forward light. When I put it in Neutral, sometimes the light on the dashboard /N lights up and sometimes it doesn't. Lastly the gas gauge does not register. Although the tank is almost full, it shows E / Empty.
By Rey Ximenes
OK, here's the mystery of the day. I was using the UTV the other day and the idiot light came on that said it was overheating. I immediately shut down and checked the coolant. No coolant! I refilled the overflow reservoir and the radiator and all was fine. 2 days later the light is on again. I rechecked the radiator and it was again empty? Bone dry? Now, here's the weird part, There is no coolant anywhere on the floor below the vehicle. I can't even see any on the frame. I have it up on the lift and am getting ready to start tearing into the bottom "skid plate" to see if the leak is in the hoses there. Any suggestions as to where to start? I have yet to begin and I am already baffled!