P1608 A/D Converter Error - ECU Repair???
 

Hi,

Would anyone know where I can get an ECU repaired in Melbourne?

So I have been having trouble with my transfer case position switch for a few months now. Every now and then it would go into limp mode. Check it with WJDiagPro and it shows the transfer case switch fault. Clear it off and away we go again. The transfer case switch is connected directly to the ECU. The ECU conditions the voltage (can be seen in the ECU values), then sends the discreet position to the TCU.

Watching the voltage, it would be rock solid most the time, then occasionally start to move around. Normally only a small amount, but then is would go wild and the fault would come up.

The wiring has a dodgy repair from the previous owner where some crappy screw terminals have been used under the car, and in a place I can't reach. Also noticed some match marks on the engine and gearbox today, so thinking the engine might have been out at some time. Noticed lately with the rain that it was playing up more, so figured it might be these terminals.

I couldn't reach them, so figured I would unplug the switch, pull the wires through and do it from the top. Well, not enough there either. The terminals now sat under the intake and I could just get one hand to them. Not enough to be able to do a proper repair.

Day was getting on, so I gave up and plugged it all back in.

For the life of me I can't think how I have blown this up, but now the car is cactus. A heap of faults that seem to be based around the A/D converter.

I have checked the voltages on the MAF, boost pressure, fuel pressure, and transfer case. All grounds and 5v supply are good. Problem is that I also have 5v on the signal wires when testing the harness.

Has anyone seen 5v on their signal wires before, and if so did the magic fix it fairies come in overnight and sort it out? I have seen posts where other people have taken ECU's for repair. If someone knows of a good place in Melbourne, any recommendations would be appreciated.

https://www.ausjeepoffroad.com/forum...e3ce6096b5.jpg

For the wiring to the transfer case switch, see https://www.ausjeepoffroad.com/forum...0&postcount=17

I soldered my new pigtail in from underneath the car. Most of it was done blind, but having poor near-field vision working by feel is a skill I have developed - as well as being pretty gun with a soldering iron. You can now get doohickies that are a combined heat-shrink-come-solder-joint which might make it easier. See https://www.ebay.com.au/itm/374920406803

Based on your original problem, it was pretty clear that you had the dreaded transfer case switch problem. I chased mine in circles for months before realising that the Dorman brand ones are incompatible with the WG. Replaced it with another brand and, presto, it all worked.

However, your newer issues appear far more sinister. You might do better to try to get a second-hand ECU and transfer the SKIM chip across as we discussed the the ECU thread. I have heard horror stories of people trying to get ECU's repaired.

To answer your real question; sorry I do not know anybody in Melbourne that does ECU repairs. That said, Robert Bosch Australia is based in Clayton. I'd contact them. You might get lucky.

EDIT:
P1608 could also be:
A to D Monitoring, RAM Test Failure
A to D Monitoring, Ground Connection to PPS Failure
A to D Monitoring, Test Voltage Failure
The diagnostics path for all these all rapidly end with "replace ECU" unfortunately.

Obvious question... have you cleared the errors to see if they come back? I would triple-check the ECU earth and the engine is well earthed.

Which wire would you like me to test for 5V? Let's do a step-by-step comparison, if you like. I am WFH tomorrow, so I can easily slip out back for 5 minutes to take a measurement, provided you pick something easy to get to and be specific.

Hi JeanLuke,

Yep, I am getting a bad feeling about this one. Could be the straw that ends the WG for me. I love it, but of all the cars I've had in my life, this one has overwhelmingly provided the most challenges. Better as a spare car, not a daily driver. It is the only car I've ever had which has come home on the back of a tow truck.

I have cleared the faults several times. Each time a different set of faults come up, but the ones previously sent are always there. Tried the master reset also, but no change.

If you could check the signal lines on the MAF and fuel pressure and let me know if you have 5v it would be great. As an example, the 3 pins on the fuel pressure for me a 0v, 5v, and 5v. Same for the boost pressure sensor. Surely the signal line should be 0v when unplugged as the voltage here should be generated by the sensor sweeper.

I have sent these guys a message to see if they can check the ECU https://www.injectronics.com.au/

Will also contact Bosch in Clayton now too.

I like your diagnostic path suggestion. When I checked the manual for the faults, it kind of gave the same feel. I will run some new earths today and see what happens.

The MAF - I removed the plug from the MAF and was measuring on the plug, with ignition on, engine off, using a Fluke 179 with the negative jammed into the battery terminal:

Yellow - 8mV
Brown/yellow - 5.012V
Brown - 8mV
Green/red - 12.2V

Not looking good.

EDIT: I couldn't quickly get the plug off the fuel pressure sensor.

Thanks JeanLuke.

That pretty much says it all. I have power where power should not be.

Injectronics have gotten back to me. 500 bucks to test it, but very unlikely that it is repairable.

Spoke to Bosch this morning. Waiting to hear back from them.

Try these guys for a second hand one, if you don't mind resoldering the security chip:
https://www.j-p-r.com/

My only concern is what sort of harness fault do I have lurking around the back of the engine somewhere??

The work I did was so mundane that I can't see how it happened. I did move the harness around a bit at the back of the engine while I was trying to get access to the terminal strip. The risk I see is that there is potentially some sort of fault back there that might just blow up the next ECU.

Really needs the engine out to have a good look back there, but not sure how keen I am to go that far.

Might pull the ECU and try and check the harness. Problem still could be that the fault is not there right now???

Might be the night to sit down with a beer and contemplate its future. Still no word from Bosch yet.