yerbito

Nobody can help me? 😞

Hi Everyone, I'm currently restoring a 2003 Cayenne. One of the issues I had was that the airbag control module couldn't be reached. After fixing that, DTCs 1738 and 1739 came up. I unplugged and cleaned the crash sensor connectors, as they had water inside. The faults went away for about a month. While waiting for the MOT (still no appointment), I kept starting the engine once or twice a week. But last week, the airbag light came back on. I connected PIWIS and again got DTC 1739 – open circuit on the front right crash sensor (the one under the right headlight). Since it had worked fine for a while, I pulled the connector and cleaned it again – but no luck. I remembered a scrapyard that had a similar car with a minor roof dent on the driver’s side and intact airbags. I grabbed the crash sensor from that side and swapped it in – still nothing. Then, when cleaning the connector again, I noticed the blue wire wasn’t as firm as the other one. I gave it a gentle pull and it snapped – completely corroded, which makes sense given how much water had come out of that connector. So I went back to the scrapyard and grabbed the connector with a bit of wire, cut and soldered it in. I know soldering isn't the best method in airbag wiring, but I wasn’t sure how much of the harness would need replacing, and the solder job is solid. I tried both sensors again – still no success. I checked continuity from both wires of the right crash sensor to the airbag module (pin 82) and to the ground point nearby – both have continuity. Then I started measuring the resistance of the sensors (plugged into a spare connector). With the multimeter hooked up correctly (– to brown, + to the other wire), I got no reading at all. If I reversed polarity, I got 0.5kΩ. What surprised me was that I got the same reading at the airbag module plug (pin 82 to ground), with the sensor connected – same results, both ways. I then measured the left crash sensor (which isn’t causing any issues – yet). It showed 2.1kΩ directly at the sensor with correct polarity, and 0.5kΩ reversed. At the airbag module connector, I got ~5kΩ. The other four crash sensors showed the same ~5kΩ at the module. I mentioned it to a friend who’s an electronics tech. He said that although 5kΩ seems high, it’s probably correct since 5 sensors measure that and don’t throw any faults. We concluded that both the original sensor and the scrapyard one were likely bad, based on their different readings. So I ordered another one off eBay from a scrapyard, and it arrived today. It measured the same as the other two at the sensor output, but once plugged in, the airbag module showed 2.5kΩ. Closer to 5kΩ, but the fault remains. At this point, I’m a bit lost – and I need to get this sorted for the MOT. Over the last few weeks I’ve also been considering keeping the car for some light off-road use, and in that case I’d probably want to remove all the crash sensors and replace them with resistors or dummy loads to avoid faults. I’d also disconnect the airbags to prevent any unexpected deployment on bumps or jumps. So, I have a few questions: How can I really tell if a crash sensor is good? Is it possible to emulate these sensors with a resistor? If so, what value should I use? As far as I understand, the crash sensors are connected directly to the airbag module and to ground, right? So continuity should be enough? Thanks in advance – even just for reading this far!

The only thing I can think of is that the part numbers for the US and Europe are different, because the only instrument clusters I can find are with my part number. I was checking something on the car using PIWIS, and when I looked into the Gateway CAN module, I found something strange. As far as I know, in my car the gateway is integrated in the instrument cluster, but I’m not sure if that’s for the CAN, the comfort system, or both. The thing is, all modules show as “OK” except for the Infotainment CAN (I don’t have a radio at the moment) and the Comfort CAN. That last one confuses me, because I’m not sure if it’s supposed to be integrated in the cluster or not. I think it is. The weirdest part is that, while I was doing these checks — engine off, handbrake on, gear lever in P — the speedometer needle suddenly started rising, and I got several alerts about the handbrake being on and the hood being open. In my car, is the Comfort CAN supposed to be handled by the instrument cluster? Also, what exactly is the “rear convenience system”?

Thanks again. In my previous message I wrote the part number incorrectly. The correct one is: 7L5920870B. I checked the label on the cluster (photo attached), but I don’t see any of the numbers you mentioned. I looked up your part numbers on Google, and on some used parts websites they claim they’re compatible with mine, but honestly, I’m not sure if that’s accurate. Several of those pages list both references (yours and mine) for the same cluster, and the label on those units also shows RB4, just like mine. Do you think it will be possible to program this cluster?

Thanks so much for your answer. I'm sorry, but I don't know which instrument cluster the car originally had. It was abandoned when I bought it, and I'm restoring it now, so I don't have much information about its previous history. I do know that the cluster was replaced at some point, because the VIN stored in it is different from the vehicle's actual VIN. My car's VIN name is: WP1ZZZ9PZ4LA43989 The VIN stored in the configuration when I bought the car was: WP1ZZZ9PZ4LA46674 Instrument Cluster part numer is: 7L592870B (RB4):

Hi everyone, I’m working on fixing several DTCs on my 2003 Cayenne, which I acquired after it had been abandoned for quite some time. It needed a lot of attention to get it back in working condition. The previous owner had replaced the instrument cluster, but I noticed that the VIN on the cluster didn’t match the car’s VIN, which seems to be causing issues. After fixing several problems — like the airbag ECU that wasn’t communicating with the DME because the CAN bus data cables were swapped,, later I need cleaning out the front airbag sensors, which had water inside — I’m now dealing with a few more issues, including errors in the ParkAssist and tire pressure monitoring modules. These errors seem to be related to the communication problems with the instrument cluster. Although I can usually clear these errors, but the HVAC system is giving me error 1299, and I can't clear it. Additionally, most of the time, I receive a timeout from this module. I’ve also been troubleshooting temperature sensor issues. I tried both a new sensor and a used one from a scrapyard, and both always show 40°C. However, I confirmed that both sensors vary their resistance correctly in hot and cold water, so they seem to be fine. When I disconnect the sensor, the cluster shows around 18°C, which is almost accurate. PIWIS, however, shows 0°C for outside temperature in the HVAC’s real-time data. After updating the VIN in the PIWIS coding section, I noticed that SG-Tausch entries 3, 6, and 7 were not configured. This might explain the ongoing errors in communication with the other modules — and probably also the HVAC timeouts. I would like know if someone konows exactly what values should be entered. Just so you know: one of the attached photos shows the VIN in case it helps in identifying the correct settings. Thanks a lot in advance for any help!