zimaria Posted June 27, 2012 Share Posted June 27, 2012 I owned a freelander 1 2006 TD4 and was involved in an accident where the front passenger side got damaged including the fender, bonnet, radiator support and shock. The vehicle has since been repaired but now the SRS light is permanently being displayed on the dashboard. I have had a diagnostic test tool attached but have been unable to reset the SRS light and there are not fault codes found. However, the following was shown on the diagnostic tool: Internal Fault replace SDM Fault is causing MIL on In spite of the above message no MIL is being displayed on the dashboard apart from the SRS light. Please can anyone assist by letting me know: 1) How to get rid of the SRS light? 2) What exactly is the SDM mentioned in the message? 3) Does the SDM really has to be replaced, and if so the cost? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 27, 2012 Share Posted June 27, 2012 At a guess the seatbelt pre-tensioner(s) may have been activated (less obvious than if the airbag has gone off!), you would have to buy new ones as they're a one-use explosive charge. Quote Link to comment Share on other sites More sharing options...
EggNChips Posted June 28, 2012 Share Posted June 28, 2012 Sure I read somewhere in the RAVE that, If any part of the SRS system deployed, then the SRS ECU cannot be reset and must be replaced Quote Link to comment Share on other sites More sharing options...
zimaria Posted June 28, 2012 Author Share Posted June 28, 2012 Thanks for the prompt responses. FridgeFreezer, please can you tell me where the pre-tensioner is located being in mind my vehicle is a TD4 2006? EggNChips, I had a quick look at the RAVE manual and couldn't find that info. Please can you confirm that the SRS ECU needs to be changed? Any idea of the cost? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 28, 2012 Share Posted June 28, 2012 FridgeFreezer, please can you tell me where the pre-tensioner is located being in mind my vehicle is a TD4 2006? I can't be sure on yours, but mine (2001) they are a black tube connected to the seatbelt clip on the side of the seat, they have a wire connected to them. They are "one piece" with the seatbelt clip. Quote Link to comment Share on other sites More sharing options...
western Posted June 28, 2012 Share Posted June 28, 2012 found this info -- in orange highlight box on attached sheet from RAVE. maybe why the SRS light can't be extinguised by testbook. Quote Link to comment Share on other sites More sharing options...
EggNChips Posted June 28, 2012 Share Posted June 28, 2012 found this info -- in orange highlight box on attached sheet from RAVE. maybe why the SRS light can't be extinguised by testbook. Yip that's the one, as for cost, not a scooby I'm afraid, not sure if they're coded to the Vehicle ECU. I would buy one from a breakers and see if it works, If not main dealer I'm afraid. Quote Link to comment Share on other sites More sharing options...
zimaria Posted June 29, 2012 Author Share Posted June 29, 2012 Thanks guys, in particular Western for proving the pertinent info from RAVE. It now means that I need to replace the airbag DCU. Any idea how much a new one cost? Quote Link to comment Share on other sites More sharing options...
zimaria Posted July 2, 2012 Author Share Posted July 2, 2012 Western or anyone else, from the article above, does it mean that once the airbag DCU enters crash lockmode the airbag and seat belt pre-tensioners become ineffective until the DCU is replaced? Quote Link to comment Share on other sites More sharing options...
kiwi_110 Posted July 3, 2012 Share Posted July 3, 2012 Yes, according to the Rave info that Western put up, the DCU is responsible for deploying the Airbags and Pre-tensioners, so without a fully functioning DCU, they are inoperative. However, tampering or short circuiting may cause them to be deployed so be careful. The way that Rave info reads, it implies that the DCU cannot trigger one restraint type without the other, it triggers both Airbags and Pre-tensioners at the same time. Did your Airbags deploy? If they did not then that could mean the crash was not sufficiently bad for the DCU to act. The DCU could be OK but is seeing another undocumented issue that is causing the DCU to hold the SRS lamp on. Also note that an intermittent fault may clear after 40 drive cycles without it recurring. Ray. Quote Link to comment Share on other sites More sharing options...
zimaria Posted July 3, 2012 Author Share Posted July 3, 2012 Hi Kiwi_110, thanks for the note of caution re tampering with the airbags / pre-tensionsers. On a second read of the RAVE info I agree that it implies that both airbags and pre-tensionsers are deployed if the DCU senses an accident. However, my airbags were not deployed and this may mean that the DCU did not enter locked mode. I am guessing that it's an intermittent problem not related to the DCU that retains the SRS light. Kiwi_110, am I right in thinking that as the intermittent fault is recurring on each ignition then it will not be cleared after 40 drive cycles? Any guess as to what other component may be faulty apart from the airbag DCU? Quote Link to comment Share on other sites More sharing options...
kiwi_110 Posted July 4, 2012 Share Posted July 4, 2012 Looking back at your original post, the diag tool you were trying to clear the fault code with clearly reported "Internal fault, replace SDM". Unless someone here knows for sure, it's only a guess that SDM = DCU. You may need to see the handbook for the diag tool you were using to find out what it means by SDM. Also, some tools other than TestBook, aren't able to communicate with all the controllers in a vehicle and only partially support some of the controller features. It might be worth trying to find another tool that might be able to do more with the SRS controller than your current tool. It's possible to fix an unknown fault without realising it, just by re-seating plugs, wiggling wires etc. If that's been the case, then after 40 cycles, the error will clear in the DCU. Also a fault may be so intermittent, that you get over 40 cycles before it happens again. I'm afraid it's a tricky one and I'm sorry I can't be more help. I have a hawkeye tool, but there's a large body of water in the way... As a last resort, and you didn't get this from me, if you were prepared to drive it with the Airbags disabled, you could follow the guidelines for making the SRS system "safe" and disconnect the SRS lamp. Ray. Quote Link to comment Share on other sites More sharing options...
zimaria Posted July 7, 2012 Author Share Posted July 7, 2012 Kiwi_110, many thanks for the info. I will look up what SDM means against the diag tool handbook. I hadn't realised that not all test tools communicate as effective as TestBook. In future I will use TestBook if I can locate one down here. On your advice this morning I am re-seating some plugs and wiggling some wires. Particular focus will be on the pre-pretensioner & seat belt buckle of driver's seat, as an experience LR peronnel mentioned these as most likey culprits. Regarding the airbag, as a safety feature, I am relunctant to disable it. Thanks for the sharing. Quote Link to comment Share on other sites More sharing options...
zimaria Posted August 3, 2012 Author Share Posted August 3, 2012 Okay, I have now wiggled, disconnected and reconnected the pre-tensioners plugs on both the driver and passenger seats. The SSR light is still there but noticed now that its goes off intermittently and comes back on when the engined is switched on. I had the vehicle connected to a diagnostic computer and the following were read: 1) Belt-pretensioner left fault: resistance too high sporadic and is causing MIL on 2) Internal Fault: Replace SDM 3) Battery too high Does anyone know whether its the pretensioner / resistor on the passenger side that needs replacing or is it the SDM (i.e. airbag DCU)? Quote Link to comment Share on other sites More sharing options...
kiwi_110 Posted August 6, 2012 Share Posted August 6, 2012 If it's possible, try swapping the plugs of the pre-tensioners around, so the system thinks it's talking to the L/H but it's actually talking to the R/H. If the fault is then reported as "Belt-pretensioner right fault", then you do have a faulty left pre-tensioner. Also try spraying contact cleaner on the plugs/sockets of the pre-tensioner cables. The hi-resistance can be a result of dirty or loose connections. Ray. Quote Link to comment Share on other sites More sharing options...
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