Bulldoggin

I took mine apart, cleaned it up and put new relays in. When I was broke down this last time it started raining and I found the leak and repaired it. I installed the waterproof relays too. The VIN is 1M1AW07Y98N003542

I have a newer model CXU. The truck ran great without a load on it. The first time I tried pulling a loaded trailer the lightning bolt (MIL) came on and the truck derated and wouldn't go over 10 mph. I drove it straight to the dealer from there which was approx 12-15 miles away. It took me over 2 hours ! That was a painful ride and boy were the people behind me PO'ed ! Lol. Anyways after the dealer checked it out, it was leaking boost air pressure through some bad charge air cooler rubber connector hoses that join the hard pipes. I had a leak in the charge air cooler itself and a leak in the EGR pipe. They replaced everything except the charge air cooler and she pulled like a Mack is supposed to after that, even while still leaking some boost out of the CAC. When you take your CL up a hill, you're putting a load on it and that's when the turbo starts to boost. In my case, the dealer blocked the air intake system and then pressurizes with air to see if it holds or leaks. Mine is an 08, and if mine was worn/cracked, then yours with 12 more years of use and abuse might have a similar issue. I was almost certain my problem was electrical/sensor related. My truck is an autoshift too, so trans is electronically controlled and wouldn't shift passed 4th gear, but ended up being a completely mechanical failure. The one connector had rubbed through on the back side so it looked fine standing and looking at it. The dealer found it by following the air leaks. You could take yours apart and inspect them really good. Good luck buddy

If you have an operator/drivers manual there is a diagram near the back of the book for both the EPDM (drivers side firewall fuse/relay box) and the BEC (Bussed Electrical center that sits in the center of the dash).

Hi there Macksters, I have an 08 Pinnacle MP8 with an EF Gen 3 autoshift and 682K on the clock. Bought it 6 months ago and I've had a recurring problem with moisture and recently water leaking into and on the EPDM. Unfortunately the Ignition relay was an unsealed variety and must have swallowed some water. Perhaps from energizing it every time I started it, it finally went nuclear and wouldn't start. About 10 fuses were burned on the legs but never popped. I believe the VECU and ABS ECU sustained some damage. I have 2 inactive codes with FMI 9, abnormal update rate, the ECU and TECU. The truck won't start because the VECU doesn't supply the 12 volts for the start enable relay and the TECU doesn't energize the start enable relay, and not allowing a reference for neutral. My question is, when I test for continuity through the J1939/CAN H & L, I have continuity to F11 (pos 12V) and several other circuits that it is connected to through both yellow and green wires. When I disconnect the circuit connectors from the VECU with the data lines still connected there is no continuity to F11, just once the circuit connectors are plugged in. There is continuity when the connector that has the data lines and other circuits is plugged into the ABS ECU. Is the continuity to F11 the interference between the ECU's that is disrupting communication ? Is the VECU and ABS the problem internally that is allowing continuity ? When I unplug the connectors and test continuity through the data line pins and other circuit pins in the ABS ECU there is none, unless the battery cable are connected. Just trying to isolate where the problem is. Any help would be greatly appreciated. Thanks