NeilF Posted December 1, 2012 Share Posted December 1, 2012 Increasingly I'm getting the three bongs and the following lights: Handbrake, TC and ABS. They go off after switching off the engine and restarting, until the next random time. I have a Hawkeye diagnostic, but it shows no DTC faults logged. Any clues from among the cognoscenti? Quote Link to comment Share on other sites More sharing options...
Fatboy Posted December 1, 2012 Share Posted December 1, 2012 Although you dont say what model / age the vehicle is, i'll take a stab at Disco 3.... and I'd think the likely candidate is a weak battery. Quote Link to comment Share on other sites More sharing options...
NeilF Posted December 1, 2012 Author Share Posted December 1, 2012 Sorry , Disco 2, 2002, facelift model. Battery starts the car easy enough......... Quote Link to comment Share on other sites More sharing options...
sierrafery Posted December 3, 2012 Share Posted December 3, 2012 does the HDC warning(the amber one) show up after ignition(on self test?) ...it's quite odd that there are no codes stored and that could lead to an ECU missbehaviour ...though if the fault is intermittent it might not store it always, especially if it's a hub issue. Quote Link to comment Share on other sites More sharing options...
NeilF Posted December 5, 2012 Author Share Posted December 5, 2012 The HDC light does come on. I read some where that minor fault codes could disappear? I'll wait until it happens again and put the Hawkeye on while the lights are still lit? Quote Link to comment Share on other sites More sharing options...
sierrafery Posted December 5, 2012 Share Posted December 5, 2012 you will not be able to connect the hawkeye while they are lit cos you have to plug it with ignition off then the tool will ask to turn ignition on and when you do that if the fault is intermittent the lights will not come on again untill you drive it... insist to read the codes untill you'll get an answer...It looks very like a hub issue to me, but you'll need to figure out which one.... it will log a fault in the end Quote Link to comment Share on other sites More sharing options...
NeilF Posted December 6, 2012 Author Share Posted December 6, 2012 But if I just plug it in with the ignition on? and then still just press the OK key when it asks to turn on ignition? Quote Link to comment Share on other sites More sharing options...
sierrafery Posted December 6, 2012 Share Posted December 6, 2012 you may try but i'm not sure it will work Quote Link to comment Share on other sites More sharing options...
NeilF Posted December 7, 2012 Author Share Posted December 7, 2012 I managed to read the fault: No. 3129, "Road Speed Missing fault logged". What does it mean? A search through past posts both here and elsewhere haven't given me any clues - this fault seems to be just one of a number in other's experience. Quote Link to comment Share on other sites More sharing options...
sierrafery Posted December 7, 2012 Share Posted December 7, 2012 this code is due to comunication failure between the engine ECU and the SLABS ECU, or again a SLABS ECU internal fault cos according to the diagnostic protocol this code is generated as "engine data" fault and it must have triggered the HDC and TC(ETC) light not the ABS, the engine ECU sends a vehicle speed signal to the SLABS which in your case it's named "road speed" and it's missing ....The engaged forward gear and (on manual gearbox models) the clutch status are computed from the engine datainput' date=' the engine speed input[u'] and vehicle speed.[/u]... this signal is known by the engine ECU as VSS(vehicle speed signal) and if it fails it must trigger the HDC lamp so first of all check for water ingress/corrosion at the SLABS ECU's plugs cos it's quite common, give them a contact spray then if this fault still persist IMO the ECU is fubar'd... quite a complicated diagnose here cos you must measure the signal on the pins if there or not to see where it gets lost Vehicle Speed Signal (VSS)The VSS is an integral part of the ECM's overall adaptive strategy. The ECM receives the signal direct from the SLABS ECU. The SLABS ECU is not connected to the controller area network (CAN) so therefore is hard wired.... ....In the case of a VSS failure on vehicles with automatic transmissions the ECM applies default values derived from the EAT ECU. There is no default value for manual transmission vehicle. The VSS can fail in the following ways: l Wiring short circuit to vehicle supply. l Wiring short circuit to vehicle earth. l Wiring open circuit. In the event of a VSS failure any of the following symptoms may be observed: l Vehicle speed limiting disabled (manual transmission only). l Hill Descent Control (HDC) warning lamp on and audible warning. . so here is an erratic behaviour along the system cos on the fault code you've got there must be other warnings see the list below with all the warning lamp protocols as conceived by the builder(your problem is with the "Engine data" ...if you have Hawkeye check on live data this VSS if you can and see how it behaves erase that fault and see if it comes on again cos it used to log erraticaly too without any efect Quote Link to comment Share on other sites More sharing options...
NeilF Posted December 7, 2012 Author Share Posted December 7, 2012 Thanks! I think........... Looked up Rave, but couldn't see a reference to SLABS ECU; is it an acronym for something? Where is it? You never know, I might just have dirty connections, if I'm lucky...... Nothing else happens when I'm driving, just the three bongs and the (wrong) three lights....... Quote Link to comment Share on other sites More sharing options...
sierrafery Posted December 7, 2012 Share Posted December 7, 2012 go to workshop manual-brakes-description and scroll down untill you find it...you'll see the connector pin descriptions and where it gets engine speed signal...pin 10- C0655 ...and so on Quote Link to comment Share on other sites More sharing options...
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