v8Dougie Posted January 30, 2013 Share Posted January 30, 2013 Hi all. The air bag light recently came on, half of it is solid on all the time, other half flashes for the first 5 mins, then stays solid on (in case that makes any difference) I have taken it to Adventure 4x4 in Leeds and they read the error informing me that there was a resistor failure in the circuit. They advised that there are a number of resistors, and due to the simple diagnosis system, were unable to determine which one it would be. They therefore said that the whole loom would have to be replaced. Anybody had this issue before? Are they correct? How much is a loom and how easy is it to replace? Many thanks in advance Cheers Phil Quote Link to comment Share on other sites More sharing options...
teabag Posted January 31, 2013 Share Posted January 31, 2013 Find some one else to look at your disco, sounds the don't know' don't care and don't wont the job. If they have such a simple system how is it they can diagnose down to componant level on a circuit board, as any resistors would be in the SRS ECU. I take it it the 1995 Td,i the rotary coupling below is known to give problems and bring up the SRS lamp in the dash and as for the loom why not ask Adventure 4x4 "How much is a loom and how easy is it to replace?".. Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 31, 2013 Share Posted January 31, 2013 Mine did this after the ECU was sat in water for a while... Failed for crossing. I ended up replacing it with another (used) ECU for about £30. I then had to have that one's fault cleared using testbook. The flashing light was present with the first ECU, the second was simply a solid light. I'd consider replacing the ECU with a used one first to see the the light changes. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted January 31, 2013 Author Share Posted January 31, 2013 Mine did this after the ECU was sat in water for a while... Failed for crossing. I ended up replacing it with another (used) ECU for about £30. I then had to have that one's fault cleared using testbook. The flashing light was present with the first ECU, the second was simply a solid light. I'd consider replacing the ECU with a used one first to see the the light changes. Thanks that is useful information and a good start. Are airbag ECUs just plug and play or do they need divorcing from the donor car and coding to the new one. Also where is it! Quote Link to comment Share on other sites More sharing options...
SPendrey Posted February 4, 2013 Share Posted February 4, 2013 Well, mine was under the centre console (cubby box area), I have the system with two crash sensors up front. It is worth checking if you have these (little red boxes about the size of 4 match boxes) mounted up behind the headlights somewhere if I recall? It is important because that'll determine the type of ECU you have. I didn't have to 'encode' mine to the car. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 6, 2013 Author Share Posted February 6, 2013 Excellent info thanks. I will have a look this weekend for the crash sensors and also lift the cubby and see what is under there. What age is yours and is it a 300tdi? Quote Link to comment Share on other sites More sharing options...
SPendrey Posted February 6, 2013 Share Posted February 6, 2013 Mine is '95 300TDI ES. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 6, 2013 Author Share Posted February 6, 2013 Will be interesting to see what bits mine has then, as mine is a '95 300TDI ES as well!! Quote Link to comment Share on other sites More sharing options...
SPendrey Posted February 6, 2013 Share Posted February 6, 2013 Does yours have endless ABS faults too then?! Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 6, 2013 Author Share Posted February 6, 2013 Nope! Sorry, none whatsoever! Light stays on until you have moved a bit and it all works fine. Makes all the lovely horrible crunches and grinds that a primitive ABS system should when used, but works a treat. Car has been off roaded a number of times as well so has been used! Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 6, 2013 Share Posted February 6, 2013 The SRS ECU is under the cubby box itself, and can be identified by having yellow convoluted wrapping for its harness (yellow is unique to the STS system wiring). I had problems with my steering wheel cassette, which i think may have broken a wire. I don't think ECU failures are common unless the vehicle has got very wet inside, and that wouldn't fit with the wiring resistance diagnosis. A cassette failure does fit that, though. The good news is that 300Tdi Discoverys and RRCs and also Discovery 2 and P38s share the same part, so getting a second hand part should be simple. BUT, make sure the steering on the donor is centralised before removing the steering wheel and cassette, and tape the cassette up on removal to make sure you don't accidentally turn it before fitting on your car, as doing so will damage it. You'll need a diagnostic system to clear the faults - once a fault is recorded, it remains logged and the warning lights stay on until the ECU is cleared - even a momentary fault will do this as it's a safety critical system and all faults are treated as needing mandatory investigation. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 7, 2013 Author Share Posted February 7, 2013 The SRS ECU is under the cubby box itself, and can be identified by having yellow convoluted wrapping for its harness (yellow is unique to the STS system wiring).I had problems with my steering wheel cassette, which i think may have broken a wire. I don't think ECU failures are common unless the vehicle has got very wet inside, and that wouldn't fit with the wiring resistance diagnosis. A cassette failure does fit that, though. The good news is that 300Tdi Discoverys and RRCs and also Discovery 2 and P38s share the same part, so getting a second hand part should be simple. BUT, make sure the steering on the donor is centralised before removing the steering wheel and cassette, and tape the cassette up on removal to make sure you don't accidentally turn it before fitting on your car, as doing so will damage it. You'll need a diagnostic system to clear the faults - once a fault is recorded, it remains logged and the warning lights stay on until the ECU is cleared - even a momentary fault will do this as it's a safety critical system and all faults are treated as needing mandatory investigation. Thanks Snagger. Take it from that you think the ECU is not at fault? Seeing as I can get a known good ECU for just £15, would it be worth swapping to test anyway? Am I right in thinking that if I disconnect battery, remove ECU, install replacement, and reconnect battery, IF the ECU is at fault then the airbag light will automatically go out (assuming the new ECU does not have a fault?) as oppose to having to have the system diagnosed again? Hope that makes sense! Also, how much am I looking for a steering wheel cassette? Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 7, 2013 Share Posted February 7, 2013 At £15, a spare ECU is a fair investment, but simply swapping them over will not extinguish the light - the new ECU will have stored a fault through being disconnected, and so will need clearing too. Your first task is to use a diagnostic tool to clear the existing stored faults and then power up the vehicle - it might be a transient fault that occurred when something was disconnected to do other work, reading as a failure. If you want to try the new ECU if that test fails, then it could be a cheap result, but if a genuine fault exists, I'd expect it to be the steering column cassette. I'd imagine you could get one from a breaker for £5 - I don't think it's a commonly needed part, even though it is the most fragile part of the system. It'd be best if you can remove it yourself so that you know it's in the central position and hasn't been turned. It's pretty simple - take the steering wheel and column trim off, disconnect it from the loom in the fuse box and unclip it from the column stalk switch assembly. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 14, 2013 Author Share Posted February 14, 2013 Thing is, when it was in for diagnosis, they read the codes, cleared them, and the light came straight back on again. They had to contact LR to find out the code pointed towards a resistor having failed. I asked if it could be the cassette but they said it would have said if it was. Does that make sense? Anyone know of anyone up in Leeds area who might be able to diagnose the system for me? Not sure if I trust the garage! Will need services anyway if I am going to change either ECU or steering wheel cassette. Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 14, 2013 Share Posted February 14, 2013 When my cassette failed, a multimeter read no contact between the two wires (ie no short) and virtually no resistance along both wires. I think there might be a scheduled resistance within the cassette, because as soon as I replaced it, the fault cleared with the ECU diagnostic tool. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 15, 2013 Author Share Posted February 15, 2013 Good enough for me! I have put the feelers out for a unit but only found them on the Bay for around £30, any suggestions where I might pick one up for the much more reasonable sounding price you mentioned?!!? Not sure where the nearest LR breaker is near me (Leeds). Cheers Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 15, 2013 Share Posted February 15, 2013 Try phoning any breakers yard near you - any 300Tdi DI, DII or P38 should have what you're after, and they usually let you have stuff like that cheaply if you remove it yourself. Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 27, 2013 Share Posted February 27, 2013 Someone is breaking a P38 on the RR section, and I think thy share the same cassette. He's just asked how to get the steering wheel off, so it looks like the cassette should be available immediately. Quote Link to comment Share on other sites More sharing options...
v8Dougie Posted February 27, 2013 Author Share Posted February 27, 2013 Thanks on it already! Fingers crossed! Quote Link to comment Share on other sites More sharing options...
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