Good morning everyone, I'm back with another issue. I recently did a cam swap on my car, which took quite a bit of time but I managed to get it done (it was my first time doing something like that). Afterward, the car started and ran fine. I even took it on a road trip with no issues whatsoever, except for the dash lights. My traction control and abs lights were on intermittently, but the brakes worked fine. However, I took it to the shop to get it fixed nonetheless, and I haven't been able to drive it since. At one shop, they replaced the ABS module but said they couldn't get the new one to communicate at all. I kept it at home for a few weeks, still driving perfectly fine, but eventually drove it to a different shop to get it looked at. The second shop says they can't get any of the modules to communicate, they're having trouble getting it started, and they started to check the wiring harness for a damaged wire but the last time I called they were talking about replacing ALL of the modules. I am sure there is something specific that causing all the fuss, but I have much less automotive electrical skill than mechanical. I was hoping you guys could give me some insight. I haven't seen my car in months, and I'm guessing it won't even run when I get it back because that's just been my luck lately. Hoping to get some ideas ahead of time.

2010 Grand Sport (manual)

 

If you can’t get ANY module to communicate their is an issue on the high or low speed CAN bus…VERY few shops and even dealerships don’t know how to diagnose this…you do NOT need to change all the modules and if they told you that you can tell them I said they should close up shop and sell hot dogs !!…they’re idiots…another post on the Forum where mechanics have no clue how to diagnose a car…if you have a DMM and know how to use it there are a few measurements we can try…if not an auto electric shop is where you should take the car…these communication issues can cause the car not to start if the ECM, BCM, and RCDLR can’t talk to one another.

 

Okay, I'll make sure that doesn't happen then. I still don't have the car back, so I can't test anything myself. I don't have much knowledge in the way of auto electric, but I can do anything with the right guide, lol. When I get the car back, I will come back to this and see if I can diagnose it myself. If I can't I'll see if I can find an auto electric shop in my area. The shop its at now came up when I googled auto electric, but I am second guessing that at this point. I really appreciate the input!

 

Basically there are a few resistance and voltage readings to be taken at the DLC where you plug a scan tool into…going between terminals 6 and 14 with the battery disconnected we expect to see approximately 60 ohms…with a voltmeter with battery reconnected we expect to see approximately 2.5 volts on pin 6 and again on 14…there are resistance reading to also be taken at 6 and again at terminal 14…the low speed bus we expect to see approximately 4 thousand ohms…an auto electric shop will normally be called Joes “Auto Electric” shop.

 

Perhaps check the ground connection to the ABS unit, which is located on the lower left side, near the front of the engine block.
On my '07 that was the problem for intermittent abs issues, it was just very lightly tightened on mine.