anthony920 Posted September 20, 2010 Share Posted September 20, 2010 Any ideas? Checked continuity and voltage on all wires at VECU. Also, checked continuity and voltage on all wires at ECU. Checked all fuses and relays - all good and voltage good. Ohm'ed J1939 wires all good. Installed good test VECU and ECU still no start. Have good fuel pressure. Computer will not talk to data link. Any suggestions will be appreciated. Ok my gynisis computer wont talk with going to try prolink tomorrow. I have also tried a new cam sensor still no start. First day checked out wiggled wires and disconnected plugs on trans and after a bit it started. Drove to yard and died at yard. Next day cleaned all battery terminals and positive and negative on chassis. Truck started, killed it and then would not restart. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/ Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 Something else driver said truck was running rough the day it started all this and the electrical light was on. Also now while starting no smoke from stack. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63828 Share on other sites More sharing options...
rhasler Posted September 20, 2010 Share Posted September 20, 2010 Any ideas? Checked continuity and voltage on all wires at VECU. Also, checked continuity and voltage on all wires at ECU. Checked all fuses and relays - all good and voltage good. Ohm'ed J1939 wires all good. Installed good test VECU and ECU still no start. Have good fuel pressure. Computer will not talk to data link. Any suggestions will be appreciated. Ok my gynisis computer wont talk with going to try prolink tomorrow. I have also tried a new cam sensor still no start. First day checked out wiggled wires and disconnected plugs on trans and after a bit it started. Drove to yard and died at yard. Next day cleaned all battery terminals and positive and negative on chassis. Truck started, killed it and then would not restart.I think trying to use the Prolink on step 10 software and higher is supposed to corrupt module data. Is you diagnostic connector 6 pin or is it 9 pin? I've seen some problems with the 9 pin connectors not communicating due to damaged or unseated pins. If your EML is flashing a 6-4 the problem is likely in the wiring to the engine or in the power up sequence of the modules. You probably have no communication on the J1587 datalink as well as on the J1939. It kind of sounds like power relay #3 may be sticking which causes incorrect power up of the modules or no power up at the engine ECU. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63831 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 It is a 9 Pin. I have checked the voltage across all 4 of the big relays with key on and they are ok. Does this have a timing sequence that may be off. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63837 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 when key is turned on it does take a few sec to hear the relays click. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63838 Share on other sites More sharing options...
rhasler Posted September 20, 2010 Share Posted September 20, 2010 It is a 9 Pin. I have checked the voltage across all 4 of the big relays with key on and they are ok. Does this have a timing sequence that may be off.The modules have to power up in sequence, VECU first EECU second. Check fuse 16 for power with the key on. This is the fuse that supplies switched power to the VECU. The VECU puts this power out on wire VJ3-13 as the control wire to the coil on the power relays. If you have power at the fuse with the key on check to see if you also have power at pin 85 on the power relays (you should). Next check that there is no power at pin 85 of the relays with the key off (you shouldn't have power there with the key off). If everything so far is ok, check pin 86 for continuity to ground (should have continuity to ground). If the coil wires (pins 85 and 86) are correct then check to see if you have power at fuse 40 (EECU power). This fuse outputs power to the EECU on wires EJ2-10, EJ2-22, and EJ2-41. If you get power here with the key on check for continuity to ground on wires EJ2-12, EJ2-24, and EJ2-43If you don't want to do all of these checks you might try replacing the power relays and checking the female terminals in the fuse panel for a loose fit, I've seen that happen more than once. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63840 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 I have checked all fuses and they have power with key on. Also VJ3-13 it has voltage,fuse 40 is good. I think I check for voltage on the EJ2 at pins at the middle three large pins i believe, and check for continuity on the bottom three. I have removed all harness protectors and checked all wires from bulkhead to EECU. Sorry I have tried to check all this, I am just at wits end don't know what else to check, thanks for your response. Could these relays just be sticking as you said, and be coming on but too late. I also switch all four of them around several times. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63842 Share on other sites More sharing options...
rhasler Posted September 20, 2010 Share Posted September 20, 2010 I have checked all fuses and they have power with key on. Also VJ3-13 it has voltage,fuse 40 is good. I think I check for voltage on the EJ2 at pins at the middle three large pins i believe, and check for continuity on the bottom three. I have removed all harness protectors and checked all wires from bulkhead to EECU. Sorry I have tried to check all this, I am just at wits end don't know what else to check, thanks for your response. Could these relays just be sticking as you said, and be coming on but too late. I also switch all four of them around several times.I wouldn't think all four power relays would go out at once. It's more likely that the pins in the fuse panel are loose, but that's not necessarily the problem either. Try checking the grounds at the engine block, frame rail, cab ground breaker, etc. Check the 15 pin connector that is over the top of the transmission too. If you have another truck you might try swapping the ECU's around. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63845 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 I cleaned the grounds at the block frame the cab ground braker on post is good although I wenta ahead and put the two wires together. I swapped the ECU with one from salvage yard not sure if its good for sure though. I checked all fuses by removing and checking for voltage then raising fuse and checking voltage on both sides. I also removed the positive cables at the frame and cleaned, they were loose and corroded so I thought I had finally found the problem. I checked the pin connector over trans and ohm'ed wires on each side of plug all ok. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63847 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 Tried ProLink today and it won't talk to it. Also, Engine Shut Down Light does not come on. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63899 Share on other sites More sharing options...
rhasler Posted September 20, 2010 Share Posted September 20, 2010 Tried ProLink today and it won't talk to it. Also, Engine Shut Down Light does not come on.If you can't communicate with it your J1587 is not functioning either. One or the other of the datalinks has to be operational to start the engine. Check for worn wires on both datlinks that may be shorting out. I am doing the same thing right now. The datlink wires for the J1939 were still intact but the insulation was rubbed through allowing an intermittant short that was causing a fault. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63900 Share on other sites More sharing options...
anthony920 Posted September 20, 2010 Author Share Posted September 20, 2010 I replaced the VECU with a 1999 model and this is a 2006 - could that be the problem? Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63901 Share on other sites More sharing options...
rhasler Posted September 20, 2010 Share Posted September 20, 2010 I replaced the VECU with a 1999 model and this is a 2006 - could that be the problem? The VECU software will not match with the EECU software and will cause a 6-4 code unless the VECU is programmed with the software and datafile for the truck by a dealer. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63904 Share on other sites More sharing options...
anthony920 Posted September 21, 2010 Author Share Posted September 21, 2010 just to mention, I didn't add the VECU and EECU, until after the 6-4 code, and I checked all powers and grounds and all where ok. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-63921 Share on other sites More sharing options...
C1065 Posted April 12, 2019 Share Posted April 12, 2019 I’m having the same problem.After the starter motor was replaced,the engine just cranks and will not start.Fuses good.Power and ground to VECU and EECU good.Any help would be appreciated.Thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-420491 Share on other sites More sharing options...
Mack Technician Posted April 12, 2019 Share Posted April 12, 2019 (edited) 4 hours ago, C1065 said: I’m having the same problem.After the starter motor was replaced,the engine just cranks and will not start.Fuses good.Power and ground to VECU and EECU good.Any help would be appreciated.Thanks. Go back in the chassis, dig around and find the power leads or ground run you did not attach to the starter post. Not everyone is getting fed. Edited April 12, 2019 by Mack Technician Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-420498 Share on other sites More sharing options...
Davesaran Posted March 2, 2020 Share Posted March 2, 2020 Any results with that vecu or ecu?. Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-444237 Share on other sites More sharing options...
Davesaran Posted March 2, 2020 Share Posted March 2, 2020 I have the same problem but I can jump start my truck through the starter. The problem started with my vecu back two weeks ago I had a blown fuse for air suspension and def lock so I went took out the fuse I didn’t had matching 15a fuse so I put 20a then oh boy some nasty smoke came out of my vecu and ya i fried my vecu still don’t know what cause that but I went out got the vecu from same truck as mine and everything worked fine just have check engine light on all the time but no problem running the truck I know I had to go to dealer to clear all the codes and have them put my Chasee number all that and all the sudden I was driving my R light for reverse gear comes and go while I’m going 115km and then it stopped every thing was fine until I pulled over in the rest area and took nap woke up I had grade gripper malfunction light on and thunder bolt light on so i thought let’s turn the truck off which was bad idea and it will not start I mean no power to starter and my mdrive start flashing ** no gears and I played with some relays and got the truck started and moved right of way from there lights comes and goes and no gear displayed got to the flaying j so I thought turn it back off this time nothing worked truck is off unless I go jump starts from the starter which I did but m drive not responding any ideas already spent $40000 on this truck this year don’t have the money to spend more any help please let me know Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-444238 Share on other sites More sharing options...
andrew smart Posted July 15, 2020 Share Posted July 15, 2020 2007 mack superliner with E7-A and eaton 18 spped ultrashift-CAN BUS J1939 wiring is not up to standard,not twisted pair or shielded both of which are required for J1939 Quote Link to comment https://www.bigmacktrucks.com/topic/15789-no-start/#findComment-455912 Share on other sites More sharing options...
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