Hello everyone, I am a new member of this website. I do have a 2014 Q7 Premium Plus. I had replaced the ABS module, and my car is not cranking anymore. When I push the start button Radiator fan is spinning very fast, but the engine is not cranking. I dont know what I should do

 

Either learn automotive or take it to a tech. Likely needs to be coded to ECU - if not flashed entirely. I just did an 08 Ford ECM repro. and that is a considerably more basic system. Take it to a decent German tech you'll pull your hair out.

 

It's a Q7, so you hookup a VAGCOM compatible diagnostic scan tool and you scan the car for internal fault codes. Hopefully you have Ross-Tech VCDS VAGCOM already. If not, then you should get one to help you with this car.

If the module you replaced is theft protected, which it likely is, then it requires the car to be hooked up to ODIS (A VW/Audi system) in order to be connected to the 'mother-ship' in Germany, which allows the module to be security coded to the car, etc. Some 3rd party shops also have ODIS on-site, but it's expensive, so that's pretty rare for anyone other than the dealerships to have it.

Is that going to keep your car from cranking over? Possibly; it's a Q7, after all...very cantankerous about security coding and start authorizations system, etc. Until you scan the car for fault codes you won't really know exactly what's going on, but the ignition key on and radiator fan goes to full blast-off mode is more likely related to bad coolant temp sensor at the radiator outler/bottom hose location at front of car...also something you can easily verify using VCDS to view the live data from said sensor. When inside the car cocoon/windows up and engine started, and/or radio on, you likely wouldn't even notice the radiator fan acting crazy like that, but it's most likely just a symptom of a different issue, IMHO. Scan the car...VAGCOM scan tool...Ross-Tech VCDS is going to save you a lot of $$$ and time. I've got three diff VAGCOM scan tools, so I am aware of what works to DIY a Q7.

You are also assuming the issue is related the ABS module you swapped out, and it may be, however, there are also well known issues that occur with no warning at all that relate to the no crank - no start issue. The fact that the car started and ran just fine until they turned it off, is what generally boggles the mind of owners. Electronics fail. If all the dash lights come on as normal, then it's not likely the start authorization problem, but if you only see the odometer and date/time display lit when turning key on, that's the tell. There's a sequence of buttons to press to manually overide and get the car to allow a VAGCOM scan tool to read it's control modules, if that's the case, etc.

Hope this helps, and good luck!!!
There's a fairly steep learning curve to DIYing a Q7

 

when i did my abs i sent it to a shop in cail for rebuild there was no coding to do, if you use a abs from a different car it more than like need to be recoded by a dealer or somebody with a vagcom

 

Hi! Let me emphasize again that your ABS module replacement may be dragging you towards the wrong conclusion...it's guilt by association, and not supported by the facts you are slowly sharing in this thread. The details are very, very important for remote troubleshooting, including those you might not deem pertinent.

Now that we know you got your original control module repaired, that changes what we know about your car and should eliminate it as a suspect.

Still, if the ABS electronic module was out of the car, then I'd suggest you do need to verify via scan tool that it shows the module is coded properly when you do a scan...this is not the same as the security coding...if you see zeros or just blank space, then that's a sign you'll need to recode the module (just not the security coding part), which you can DIY no problem with a capable VAGCOM scan tool and reviewing prior scans of your car to retrieve the coding. If it's coded and looks great, then move on to find the actual underlying cause of your No Crank issue.

Pretty much all advice/recommends discussed so far was based on the incomplete information you provided in your opening post to this thread. For blank slate No-Crank issue, there are both dedicated archival threads and online videos to illustrate the known causes of a NO-CRANK situation. If you turn the key in ignition and your normal test sequence of the warning lamps does not illuminate, and you can't scan the car for faults, that means you have the known issue with the authorization module under the dash. There's a special sequence of buttons and levers to press, which will enable the scan tool to connect and scan car/show you the fault codes.

If your warning lights on dash do light up normally, but won't crank, then you will be able to scan car and also to verify the basics: Battery/voltage, ground cable to chassis under car is tight/not corroded/loose, and the dead-man switch on brake pedal is good, and the neutral safety switch is also working, etc., and a mechanic will also give the starter a love tap or two to verify if it just has a flat spot/going out, which you don't want, as that is a real PITA to swap out, but it happens.