Mack Granite Crank No Start
2005 Mack Granite CV713, 1M2AG11CX5M017303, ESN 4V1962, A1-427 ASET IEGR,
Crank No Start. Truck was running fine. Driver shut it off for lunch at McDonalds. Has not started since.
We do have fuel pressure of and volume. To confirm that we currently have an auxiliary electric fuel pump on it.
ECM is not firing the injectors. Have tried two test ECM’s. Have VMAC III software and can communicate but am not proficent with the software. Get different sets of codes. Blink code 6-4 J1939 data link intermittent seems consistent. Have found some SI online but need more. Especially wiring diagrams We are being told the VECU has to be working and communicating.
When trying to monitor ECM data I do not see engine RPM but the tach is registering. If I unplug the speed sensors at the front and back of engine I get codes. Where is the VCEU? If it is in the dash how deep? Any common harness failure points? Suggestions.
Hi Rex, I recommend disconnecting Positive and Negative battery power and cross the cable together for about 30 minutes. This will discharge all system capacitors. While cables are disconnected, do an ohm test on all fuses to make sure none are blown or cracked from stress/ age. Replace any that are bad. After all that is done reconnect power and see if it will fire up and go and all…
Interesting, have not done that in so long I forgot about it. I don't think it was ever a thing with Navistar except maybe DLB. I know it was with Ford Powerstrokes especislly after injector replacement. At least on the T444E. Thanks
Vecu is on the right side bottom dash, just a few T-27’s and you have access to vecu and abs ecu, make sure data link or power supply to vecu is not rubbed through anywhere on that steel plate its mounted to. Most diagrams are actually available from the mack website.
I will take a look. I was on the Mack website over the weekend and could not find anything that old. Could you post a link? Thanks for the location info.
Macktrucks.vg-emedia.com You can also Google mack body builder support and find a lot of info and diagrams that way
Thanks, thats what I had seen. Found the DVD on ebay and ordered. I figure with it on non returnable order I will have have this fixed by the time it gets here. If I don't order I will be wishing I had it 5 days from now.
secure.macktrucks.com/spubs/wiring/G…; See if this link works for you or if it asks for a login
I would look really close at the harness before plugging in another ECM. You could have a rubbed through area. Hopefully the 2 test ECU's aren't smoked.
I think I am OK because we checked the wiring at the ECM connectors last week. Powers and grounds appear to be where they are supposed to be but will be back on it today. Thanks
On this engine I think the dash tach is on a seperate circuit, dont forget the usual, power and grounds, harness problems, I have started using headlite bulbs to create a controlled load on a circuit, that has helped me a lot on wires that are partially corroded or a bad connection, is the ecu actully commicating? Good luck.
Were you able to fix this yet?? EUP harnesses like to break at the Right rear corner where it bends around the block , But in My opinion, to loose all of them at the same time is unlikely. Individual EUP wires get hard and brittle and like to short against each other & the tin cover and cause a miss. Again , unlikely to cause a no start. If you lose an engine position sensor , The fly wheel…
Not fixed yet. It is a 2 plug IEGR engine. Back on it this morning. First check will be for 1939 at the ECM. Also … SI is not clear but if ECU does not see 1939 that might be the no start. When I try to monitor engine speed, oil pressure etc with the VMAC-III software I am not seeing it.It cranks well. Will check that back corner. What is EUP? Thank you for responding.
electronic unit pump = EUP Camshaft driven injection pump Any luck yet?? From experience , 60 psi is the low limit for fuel pressure … it may just be fine, it may not… Is there anything holding the ck ball open in the fuel return fitting?? (the one just aft from the hose connection on the supply galley)
Still doing the same thing. Almost starts. Dies as soon as I stop cranking. Per the Mack dealer 60 psi is fine. Monday I an going the scope the injectors, or at least try, new to scoping. SI only shows 3 powers going to the ECM. They are are good KOEO and have load tested the with a headlight that draws a bit ove 4 amps. If this link works you can listen to it. Any and all ideas welcome…
Some progress but still not running. Unplugged the VECU and plugged it back in. Read somewhere it is tied to the EECM. Anyway the injectors are now firing. While cranking it will get up to 5-600 RPM and I'm getting some smoke out the stack. As soon as I let off the key it dies. Have 60 psi fuel pressure with new fuel pump. NO codes.
Did you study the ecm wiring schematic ? I once worked on a 3406c w peec ecm, it had an ecm input from starter, which would power the ecm when missing the ignition switch power, good luck
Went over the wiring as best I could with no improvement. With some help was able to scope the injectors. They are firing. I had to let it go, aka give up. Something I rarely do. Customer needs the truck. Sent it to the Mack dealer. They have a tech who has been with them for at least 30 years and seems to know his stuff from the conversations we had. FWIW I suspect there might be a compression…
Waiting for the Mack dealer. Folded on this one. They are replacing the engine wiring harness and ECM. I still suspect a compression or some base engine issue. I WILL update this when it is fixed.
This engine has 6 electronic camshaft driven unit pump but old style manual injectors under the valve covers,,,