The Dilemma of the Duplicitous Mod,
or “When Good gapTechs Go Bad”
....
Note to readers:
This post will be of absolutely NO interest to those who have not installed the gapTech OTH, RCH or OTH+R mods, and of only passing interest to those who HAVE installed one of them -- until (and if) something goes amiss. Yes, electronics do occasionally fail.
I post with the singular purpose of potentially saving considerable frustration in the unlikely case that such installers might – somewhere, someday – find themselves in a similar quandary as that from which I recently emerged.
Let me be clear at the outset that I remain a steadfast advocate for the gapTech Remote Control / One Touch Hood modification (see http://gap-tech.co.uk/). I can also personally vouch for the unimpeachable customer service I have received from Gary, the owner and developer of the gapTech brand (btw, his initials are G.A.P., thus the marque).
As background, I purchased the OTH+R (one touch hood plus remote) module back in April 2011 during the inaugural Group Buy here on the forum. Immediately upon trouble-free installation, the mod became my favorite on the Z4, and one of the best I’ve ever made to ANY BMW (and I’ve made lots since the early 80s). It performed flawlessly until about two weeks ago, when I began to have electrical issues, followed by various K-bus malfunctions. While it is now clear that those issues resulted from the failure of the OTH+R module, the troubleshooting involved in arriving at that conclusion was far from easy.
The subject car is our 2008 E85 Z4 3.0si roadster. My first indication that something was amiss was when my battery discharged overnight to the point that it needed to be jump started in the morning. I assumed at that point, without verifying, that I had left a light on, or something of that nature, and moved on. I did not have occasion to drive the car that day, so it wasn’t until the next that I realized that, although the car would start without issue, the SRS (Airbag) light had illuminated, the TPS inflation warning was flashing, the passenger airbag occupancy light (next to the shifter) was illuminated, the soft top up/down buttons no longer functioned, the turn signals did not operate, the radio was inoperable, and the air conditioner compressor would not engage, i.e. blower only. With each successive revelation of malfunction, I was increasingly overjoyed, as I have little else in life to do but to chase automotive electrical gremlins.
Research on this and other fora pointed to a possible computer system reversion to the (so-called) ‘transport mode’ – perhaps occasioned by the battery discharge – so things began to point rapidly towards a trip to the dealer (with whom I do have a very good relationship). Note that the car was now THREE days out of the manufacturer’s warranty, but thankfully still within the extended two years of the CPO warranty. A possible OTH+R module failure had not yet crossed my simple mind.
On the way to the dealer’s (a half hour drive), some of the faults began to mysteriously resolve themselves. The radio came on, but the volume was frozen (perhaps an amp issue, I thought, to conserve power). Then the turn signals resumed functionality and the air conditioner began to work. I did not have the courage to test the roof function, as my fortunes of late had not been promising, and I was indeed satisfied to have the roof in the closed position until such fortunes changed for the better.
Late in the day, the dealer called to inform me that it was NOT a simple transport mode issue, and that the computer diagnosis was throwing odd K-bus and system irregularities. Something looked like a short in the bus wiring. They’d need to keep the car overnight for additional troubleshooting. Wonderful. Perfect.
At this point, the flickering thought of a possible OTH+R module failure began to cross my mind, but I still understood at that point that, while low importance functions like the stereo do communicate using the K-Bus (which is indeed used by the OTH+R), the safety critical functions use a higher priority bus which is not used by the module.
Furthermore, late word from the dealer purported to confirm that the issue was NOT the module, as they had traced a fault with the passenger’s seat occupancy sensor mat, and had replaced it under CPO ( we’d had a similar replacement in an E90, so I was familiar with the job). I was informed that all lights were now clear, all systems were normal again, and that I was welcome to retrieve the car that evening. Excellent.
As the porter relinquished the car back to me, and I slipped triumphantly into the driver’s seat, my horror was exhumed in an instant as I noted that the dash was now lit up like a Christmas tree with every light I had previously complained of, plus a few more for good measure. Wonderful. Perfect.
My service writer was perplexed, perhaps ashamed, and I was invited to again leave the car, but opted to just take the car home and think things over a bit. By the time I arrived home, many of the functions were again operable, and the safe harbor of my garage gave me the courage to test the soft top buttons on the console. Both worked fine, but I noticed that the ‘one touch’ feature of the OTH+R had disappeared, as it was again necessary to depress and hold the buttons for soft top operation. Likewise, the remote feature of the module had ceased to operate. Hmmm. Maybe it was indeed the module. I resolved to remove it come morning.
Once I gained access to the module, a visual inspection of the site revealed nothing amiss, i.e. no obvious shorts, melting, loose connections, etc. All scotch-loks (which worked fine for me for 13 months) were intact, and there was no smell of fried circuit boards, etc. To facilitate re-installation, I removed the module by simply snipping and capping the 5 wires (key out of ignition, but I did not remove the negative battery terminal). When I cut the red wire, there was a short beep that seemed to come from the dash area.
Starting the car with talismans and prayers aplenty, I was overjoyed (nay, ecstatic) to see that removal of the unit had cleared all faults save the SRS light -- which must of course be reset by the dealer (or with dedicated software), and which warning I fully expected to extinguish without recurrence once reset by the dealer. All of the various and sundry additional oddities resolved themselves once the module was removed, and a dealer reset of the SRS light has indeed ‘taken’ just fine.
Testing of the faulty module by gapTech verified that, although everything seemed to work fine when first connected to the test jig, a test soak after about 15 minutes caused the module to start spitting out random data on the bus. Gary had never seen this behavior before and postulated that it could just be a faulty microcontroller. It seems like there may have been an intermittent shorting of K-bus functions occasioned by the module, which would appear and disappear randomly.
Of course, I was now without my OTH+R, and I may be a glutton for punishment, but I wanted it back. Gary was quite gracious in sending out a gratis replacement, even though the original was about a month out of the one-year warranty, and I have also purchased an additional unit as a spare in connection with the current Group Buy.
One additional note -
Upon re-installation of the new OTH+R by simply re-connecting the same five colored wires, and putting things back together, my top still refused to function as per the OTH+R features. Wonderful. Perfect. The new unit did not work once installed. To spare you from the troubleshooting and gnashing of teeth involved in this nice little problem, it turned out that the #5 15 amp cigarette lighter/accessory fuse had blown during the various earlier troubleshooting exercises. Once replaced, all was well, so it is worth noting that the module is powered by the cigarette lighter/accessory circuit, and that one of the first things to check in the case of simple malfunction may be the #5 fuse.
I do hope that this detailed recounting of my recent dilemma may be of some use to some other poor bastard somewhere . . . someday . . . frustrated and bewildered down the line.
Cheers!
or “When Good gapTechs Go Bad”
....
Note to readers:
This post will be of absolutely NO interest to those who have not installed the gapTech OTH, RCH or OTH+R mods, and of only passing interest to those who HAVE installed one of them -- until (and if) something goes amiss. Yes, electronics do occasionally fail.
I post with the singular purpose of potentially saving considerable frustration in the unlikely case that such installers might – somewhere, someday – find themselves in a similar quandary as that from which I recently emerged.
Let me be clear at the outset that I remain a steadfast advocate for the gapTech Remote Control / One Touch Hood modification (see http://gap-tech.co.uk/). I can also personally vouch for the unimpeachable customer service I have received from Gary, the owner and developer of the gapTech brand (btw, his initials are G.A.P., thus the marque).
As background, I purchased the OTH+R (one touch hood plus remote) module back in April 2011 during the inaugural Group Buy here on the forum. Immediately upon trouble-free installation, the mod became my favorite on the Z4, and one of the best I’ve ever made to ANY BMW (and I’ve made lots since the early 80s). It performed flawlessly until about two weeks ago, when I began to have electrical issues, followed by various K-bus malfunctions. While it is now clear that those issues resulted from the failure of the OTH+R module, the troubleshooting involved in arriving at that conclusion was far from easy.
The subject car is our 2008 E85 Z4 3.0si roadster. My first indication that something was amiss was when my battery discharged overnight to the point that it needed to be jump started in the morning. I assumed at that point, without verifying, that I had left a light on, or something of that nature, and moved on. I did not have occasion to drive the car that day, so it wasn’t until the next that I realized that, although the car would start without issue, the SRS (Airbag) light had illuminated, the TPS inflation warning was flashing, the passenger airbag occupancy light (next to the shifter) was illuminated, the soft top up/down buttons no longer functioned, the turn signals did not operate, the radio was inoperable, and the air conditioner compressor would not engage, i.e. blower only. With each successive revelation of malfunction, I was increasingly overjoyed, as I have little else in life to do but to chase automotive electrical gremlins.
Research on this and other fora pointed to a possible computer system reversion to the (so-called) ‘transport mode’ – perhaps occasioned by the battery discharge – so things began to point rapidly towards a trip to the dealer (with whom I do have a very good relationship). Note that the car was now THREE days out of the manufacturer’s warranty, but thankfully still within the extended two years of the CPO warranty. A possible OTH+R module failure had not yet crossed my simple mind.
On the way to the dealer’s (a half hour drive), some of the faults began to mysteriously resolve themselves. The radio came on, but the volume was frozen (perhaps an amp issue, I thought, to conserve power). Then the turn signals resumed functionality and the air conditioner began to work. I did not have the courage to test the roof function, as my fortunes of late had not been promising, and I was indeed satisfied to have the roof in the closed position until such fortunes changed for the better.
Late in the day, the dealer called to inform me that it was NOT a simple transport mode issue, and that the computer diagnosis was throwing odd K-bus and system irregularities. Something looked like a short in the bus wiring. They’d need to keep the car overnight for additional troubleshooting. Wonderful. Perfect.
At this point, the flickering thought of a possible OTH+R module failure began to cross my mind, but I still understood at that point that, while low importance functions like the stereo do communicate using the K-Bus (which is indeed used by the OTH+R), the safety critical functions use a higher priority bus which is not used by the module.
Furthermore, late word from the dealer purported to confirm that the issue was NOT the module, as they had traced a fault with the passenger’s seat occupancy sensor mat, and had replaced it under CPO ( we’d had a similar replacement in an E90, so I was familiar with the job). I was informed that all lights were now clear, all systems were normal again, and that I was welcome to retrieve the car that evening. Excellent.
As the porter relinquished the car back to me, and I slipped triumphantly into the driver’s seat, my horror was exhumed in an instant as I noted that the dash was now lit up like a Christmas tree with every light I had previously complained of, plus a few more for good measure. Wonderful. Perfect.
My service writer was perplexed, perhaps ashamed, and I was invited to again leave the car, but opted to just take the car home and think things over a bit. By the time I arrived home, many of the functions were again operable, and the safe harbor of my garage gave me the courage to test the soft top buttons on the console. Both worked fine, but I noticed that the ‘one touch’ feature of the OTH+R had disappeared, as it was again necessary to depress and hold the buttons for soft top operation. Likewise, the remote feature of the module had ceased to operate. Hmmm. Maybe it was indeed the module. I resolved to remove it come morning.
Once I gained access to the module, a visual inspection of the site revealed nothing amiss, i.e. no obvious shorts, melting, loose connections, etc. All scotch-loks (which worked fine for me for 13 months) were intact, and there was no smell of fried circuit boards, etc. To facilitate re-installation, I removed the module by simply snipping and capping the 5 wires (key out of ignition, but I did not remove the negative battery terminal). When I cut the red wire, there was a short beep that seemed to come from the dash area.
Starting the car with talismans and prayers aplenty, I was overjoyed (nay, ecstatic) to see that removal of the unit had cleared all faults save the SRS light -- which must of course be reset by the dealer (or with dedicated software), and which warning I fully expected to extinguish without recurrence once reset by the dealer. All of the various and sundry additional oddities resolved themselves once the module was removed, and a dealer reset of the SRS light has indeed ‘taken’ just fine.
Testing of the faulty module by gapTech verified that, although everything seemed to work fine when first connected to the test jig, a test soak after about 15 minutes caused the module to start spitting out random data on the bus. Gary had never seen this behavior before and postulated that it could just be a faulty microcontroller. It seems like there may have been an intermittent shorting of K-bus functions occasioned by the module, which would appear and disappear randomly.
Of course, I was now without my OTH+R, and I may be a glutton for punishment, but I wanted it back. Gary was quite gracious in sending out a gratis replacement, even though the original was about a month out of the one-year warranty, and I have also purchased an additional unit as a spare in connection with the current Group Buy.
One additional note -
Upon re-installation of the new OTH+R by simply re-connecting the same five colored wires, and putting things back together, my top still refused to function as per the OTH+R features. Wonderful. Perfect. The new unit did not work once installed. To spare you from the troubleshooting and gnashing of teeth involved in this nice little problem, it turned out that the #5 15 amp cigarette lighter/accessory fuse had blown during the various earlier troubleshooting exercises. Once replaced, all was well, so it is worth noting that the module is powered by the cigarette lighter/accessory circuit, and that one of the first things to check in the case of simple malfunction may be the #5 fuse.
I do hope that this detailed recounting of my recent dilemma may be of some use to some other poor bastard somewhere . . . someday . . . frustrated and bewildered down the line.
Cheers!
