Aj_

Hello, my z was driving just fine until I got codes “U1000” and “U1001” now it doesn’t crank at all. I was wondering if a faulty ac amp could be the problem if not what could be some possible fixes? Thanks in advanced.

icer5160

iTrader: (4)

I don't think so. Both of these codes refer to modules not being able to communicate over the CAN bus, typically caused by a wiring fault. First, check your major ground connections in the engine bay. A bad ground could cause odd behavior with the computer modules, this is where I would start. Another possibility is a wire has been cut that shouldn't have been or a wire is shorting to ground or to another wire in a bundle (compromised shielding from rubbing/vibration against a sharp edge, or melted from aftermarket electrical addons improperly installed). If you've done any work involving the tampering/tinkering with the wire harness recently, go back and inspect those areas of the harness.

What makes you bring up the AC Amp, just curious as that component is not related to these codes.
-Icer

Aj_

Thank you I will check all those things out. I was completely lost regarding these codes. The reason I mentioned the amp was because I found the ambient air sensor the one in the front of the car around the hood latch area with the wires cut and I thought that it might of shorted something out and I followed the wires with the diagram which led to the amp I just assumed it might of messed it up or something lol

MicVelo

Another consideration: have you had the car tuned (not plugs n' stuff, ECM parameter tune) recently? There have been instances noted where ECM changes or faults in the ECM will create a communications problem over the LAN (CAN bus, which is a local area network). Or have you had any sensors changed at all?

Aj_

Thank you.
I don’t believe the car has been tuned, I haven’t at least I’m not sure about the previous owner but I doubt he did. The only sensor I recall changing was the oil pressure sensor lol but that was a while ago I’ll try to remember if I changed any others. It just sucks because it was driving normally then the next day it won’t turn on. But I’ll check over carefully everything you guys mentioned. The information and help you guys gave is very much appreciated🙏

icer5160

iTrader: (4)

Ok, cut wires in evidence. I would definitely get that resolved for starters. At the very least, make sure the cut ends cannot short across to anything. Cap them and just leave that sensor circuit open. Ideally, the sensor and harness should be replaced/repaired. Based on the diagram that sensor only communicates with the A/C module, but as you also mentioned, the A/C module has CAN bus data lines to the rest of the car's network. If the A/C amp has been damaged/killed it *should* not impact the entire CAN bus, the other modules like the PCM and BCM should still be able to communicate, but it's a possibility. You can try to unplug the A/C control module completely to rule out this component, the engine should still start with this system disconnected (Blower fan may go to full max with it unplugged, normal behavior). I personally suspect the root cause is something else. Start with the most obvious stuff and go from there. If none of the obvious checks/fixes yield results, I highly recommend seeking professional help from a shop that specializes in automotive electronic diagnosis/troubleshooting. You will need live data probes and detailed wiring diagrams to analyze the signals on the CAN bus to trace down the root cause, otherwise it's just guess work.

Good Luck!
-Icer

Aj_

Dang that doesn’t sound fun or easy😅 but I’ll give it my best shot I’ll look carefully at everything you guys mentioned above hopefully I can figure this out if not I’ll take it to a pro like you said. Thank you very much for the advice🙏

Dannyz.34

We’re you able to resolve this? Im having a similar no crank, no start issue on my 370Z. I’m getting a can communication code as well. I have looked through all the wiring and changed out several modules including the ecu, bcm, IPDM, and harnesses. I haven’t changed the a/c amplifier but after reading this thread I feel that it may be the issue. Let me know if you were able to resolve the issue. Thanks