Ratslaaf
///Member
This is a repost from AudiFanatics. Things are dead there and I figured this can be valuable information for other Audi owners. Seeing what Audi asks for a replacement DRL module, that is known to have a design problem as my findings below will confirm...
A week or so ago, the wife's Q5 Right DRL went dead. She has also been having an issue with the AC blower so I figured I'd spend the day and check it out.
First off, I stripped the whole headlight out of the car as the DRL controller sits inside the headlight. This, my friends, was not an easy undertaking as it's the bumper and various bits, brackets, manifolds and another million things to strip off. But yay, I had the headlight out eventually.
Imagine my surprise when I realised I could've just removed the one back cover, unscrew two bolts and the controller would come out. Easy Peasy. Today was going to be one of those days...
So, while I sit and have a smoke, I read up about the DRL's and, surprise surprise, this is another one of those issues with '09 and '10 Audi's - the DRL modules are a real problem. This seems to be for all cars, not just the Q5's. Looking at pricing I was going to pay over R5k for a module from the agents. And with the car now 4 months out of plan, I doubt Audi will entertain any goodwill gestures, even though they know it's a problem.
I then opened the unit up to have a look if it's at all serviceable and it looked like the kind of thing I can fix, being an electronics guy. In order to make my life easier, I remove the other DRL as well so that I can compare the two on my bench when fault finding. And guess what, the other side has already been replaced
I know this because it was only held on with one screw (not two like it should be) and it had a 'B' suffix after the part code.
Here we go with the two units next to each other, new one on the left.
I believe that the revised module had a fix applied to it in order to make it more reliable. Well, to be honest, they only made one fix and that was changing one diode to a larger one. See below, with the only change made between the boards marked with a black circle.
And
I didn't even bother doing any further fault finding, I simply powered the faulty one up on the bench and sure enough, the SOT23 diode was blown. I'd hazard a guess that this diode is rated for around a 1A and the new one for 3A. I didn't have any 3A diodes in my bin and with some testing on the new module I determine there's nothing fancy about the new diode (it's not a Shottky type), it's just a plain general purpose 3A power diode. I had a handful of 1N4007's here, that are rated for only 1A but I connected two in parallel in order to improve power handling. There's nothing further down the chain that needs more power than that so I just went with it. If it does break again (which I seriously doubt) then I'll get the correct type.
Anyway, here's the fix applied. I didn't remove the faulty diode as it simply went open circuit so wouldn't interfere with the fix. These modules are so covered in conformal coating, trying to remove the old diode would just make a mess.
After the repair, I quickly connected the Right headlight again to test and, Voila!
Now the nightmare of assembling the whole car again, but getting it fixed for the princely sum of two 50c diodes made it worth it Bluebiggrin
Next up, I needed to figure out what's going on with the AC. Basically, the AC works when the car is cold, but when you drove for a while and switched the car off and then on again a minute or so later the AC won't work.
So I drove around for a bit today and sure enough the problem popped up. The display works fine and I can control everything, there's just no air coming out. I let the car idle and then switched the AC on and off and I can hear it kicking in. I can also change the air direction and can hear the flaps opening and closing but there's no air coming out of the vents. So it's definitely something to do with the Blower motor.
This was another arduous task, as the blower motor sits behind the Glove Box. It literally took me an hour to get the glove box out as there was this one last screw that held the lot together that I couldn't find. There's a cavity for the CD changer in the glove box, but seeing as this car doesn't have one there's just a little shelf installed there. Look as I want, I can't figure out how to remove this little shelf - it got to a point where I was going to fetch the crowbar to get the lot out.
Had a smoke and calmed down a little. I had another look with a torch and I see two very well hidden clips that you need to pull in with a screwdriver and the shelf came out. Whew!!
I switched the car on, and blower not working. The motor controller is attached to the motor, so I simply pulled the plug to the motor controller, plugged it back in and hey presto - the blower started working! There's 3 wires going to the controller, two for power and one I assume to be a signal wire to tell the controller how hard to drive the motor. Based on the fact that this is a non feedback system (failure in the motor controller won't throw up any errors) and that simply re-seating the connector fixed the problem, I'm pretty sure I located the culprits and that the problem isn't somewhere further up the line.
It was late so didn't go for a drive again, but this is the kind of thing that will pop up again. I will clean the terminal contacts to the motor controller as a precaution and monitor it over the next few weeks. If it pops up again it's either the controller or the motor and then I'll revisit the issue again.
A week or so ago, the wife's Q5 Right DRL went dead. She has also been having an issue with the AC blower so I figured I'd spend the day and check it out.
First off, I stripped the whole headlight out of the car as the DRL controller sits inside the headlight. This, my friends, was not an easy undertaking as it's the bumper and various bits, brackets, manifolds and another million things to strip off. But yay, I had the headlight out eventually.
Imagine my surprise when I realised I could've just removed the one back cover, unscrew two bolts and the controller would come out. Easy Peasy. Today was going to be one of those days...
So, while I sit and have a smoke, I read up about the DRL's and, surprise surprise, this is another one of those issues with '09 and '10 Audi's - the DRL modules are a real problem. This seems to be for all cars, not just the Q5's. Looking at pricing I was going to pay over R5k for a module from the agents. And with the car now 4 months out of plan, I doubt Audi will entertain any goodwill gestures, even though they know it's a problem.
I then opened the unit up to have a look if it's at all serviceable and it looked like the kind of thing I can fix, being an electronics guy. In order to make my life easier, I remove the other DRL as well so that I can compare the two on my bench when fault finding. And guess what, the other side has already been replaced
I know this because it was only held on with one screw (not two like it should be) and it had a 'B' suffix after the part code.Here we go with the two units next to each other, new one on the left.
I believe that the revised module had a fix applied to it in order to make it more reliable. Well, to be honest, they only made one fix and that was changing one diode to a larger one. See below, with the only change made between the boards marked with a black circle.
And
I didn't even bother doing any further fault finding, I simply powered the faulty one up on the bench and sure enough, the SOT23 diode was blown. I'd hazard a guess that this diode is rated for around a 1A and the new one for 3A. I didn't have any 3A diodes in my bin and with some testing on the new module I determine there's nothing fancy about the new diode (it's not a Shottky type), it's just a plain general purpose 3A power diode. I had a handful of 1N4007's here, that are rated for only 1A but I connected two in parallel in order to improve power handling. There's nothing further down the chain that needs more power than that so I just went with it. If it does break again (which I seriously doubt) then I'll get the correct type.
Anyway, here's the fix applied. I didn't remove the faulty diode as it simply went open circuit so wouldn't interfere with the fix. These modules are so covered in conformal coating, trying to remove the old diode would just make a mess.
After the repair, I quickly connected the Right headlight again to test and, Voila!
Now the nightmare of assembling the whole car again, but getting it fixed for the princely sum of two 50c diodes made it worth it Bluebiggrin
Next up, I needed to figure out what's going on with the AC. Basically, the AC works when the car is cold, but when you drove for a while and switched the car off and then on again a minute or so later the AC won't work.
So I drove around for a bit today and sure enough the problem popped up. The display works fine and I can control everything, there's just no air coming out. I let the car idle and then switched the AC on and off and I can hear it kicking in. I can also change the air direction and can hear the flaps opening and closing but there's no air coming out of the vents. So it's definitely something to do with the Blower motor.
This was another arduous task, as the blower motor sits behind the Glove Box. It literally took me an hour to get the glove box out as there was this one last screw that held the lot together that I couldn't find. There's a cavity for the CD changer in the glove box, but seeing as this car doesn't have one there's just a little shelf installed there. Look as I want, I can't figure out how to remove this little shelf - it got to a point where I was going to fetch the crowbar to get the lot out.
Had a smoke and calmed down a little. I had another look with a torch and I see two very well hidden clips that you need to pull in with a screwdriver and the shelf came out. Whew!!
I switched the car on, and blower not working. The motor controller is attached to the motor, so I simply pulled the plug to the motor controller, plugged it back in and hey presto - the blower started working! There's 3 wires going to the controller, two for power and one I assume to be a signal wire to tell the controller how hard to drive the motor. Based on the fact that this is a non feedback system (failure in the motor controller won't throw up any errors) and that simply re-seating the connector fixed the problem, I'm pretty sure I located the culprits and that the problem isn't somewhere further up the line.
It was late so didn't go for a drive again, but this is the kind of thing that will pop up again. I will clean the terminal contacts to the motor controller as a precaution and monitor it over the next few weeks. If it pops up again it's either the controller or the motor and then I'll revisit the issue again.
