Jonny Wallin Posted November 17, 2008 Report Share Posted November 17, 2008 Hi all! I´m a new member from Sweden. I hope that someone in the big country has some experience of my failure. My STS is new bought. My failure is. When the car is cold and I drive away the ABS and TC lamps light up for 2 minutes. During this time I cant release the handbrake. Have to do that manualy. After 2 minutes all lamps is okay and everyting is normal and works. Even the electrical handbrake realiser. My failure codes are: U1040 Loss of Class 2 Communications with ABS U1255 Class 2 Initialization Error ??? P1602 Loss of EBTCM Serial Data ??? C1780 Loss of Steering Position Signal C1783 ICCS2 DL Left Output Short CKT to GND ???? C1785 ICCS2 DL Right Output Short CKT to GND ??? There has to be some connection on all of this failures. If I clear all this codes, during engine on, and drive for a couple of hours.It will not be any new codes. Only after a new cold start next day. Can any one explain what to do for fault finding myself. Regards Jonny Link to comment Share on other sites More sharing options...
SwampeastMike Posted November 17, 2008 Report Share Posted November 17, 2008 The common component for all these codes is the EBTCM (Electronic Brake, Traction Control Module). The EBTCM is in the engine compartment at the bottom of the left front underneath the air cleaner housing attached to the brake pressure modulator valve. You might want to verify that the connector is clean, undamaged and properly attached to the module and also that the dedicated ground wire (it breaks out right before the connector) has a firm, clean connection. If you do not find any obvious problem in/around the wiring and connector, it would [seem] to be a problem in the EBTCM itself or the serial data line. You'll really need a service manual and decent digital multimeter to proceed much further--access to a good scan tool (Tech-II if at all possible) would definitely help as well. Link to comment Share on other sites More sharing options...
Jonny Wallin Posted November 17, 2008 Author Report Share Posted November 17, 2008 Hi! This was a fast answer. Of cause my first "try to repair" will be what you wrote. I´l be back with answer how it went. Regards Jonny Link to comment Share on other sites More sharing options...
SwampeastMike Posted November 17, 2008 Report Share Posted November 17, 2008 Hi! This was a fast answer. Of cause my first "try to repair" will be what you wrote. I´l be back with answer how it went. Regards Jonny I wish you luck and hope you find a simple problem. The first three error codes you listed have to do with detecting, initializing and maintaining serial communication with the EBTCM over the class 2 serial line. The next three are inputs (over individual, dedicated wires) from the CVRSS (continuously variable road sensing suspension) module located behind the rear seat on the right side. I'm not a professional mechanic and have only owned my 99 STS for about a year. Body and interior quite good but it very cheap as water pump and radiator were shot (known) but also had a blown head gasket. After these expensive repairs, I've gotten really good at making other repairs myself and I've always been good at troubleshooting electrical/electronic problems in anything. As best as I can tell from the service manual, the EBTCM sure seems to be the root of the problem. The various control modules are highly inter-related and inter-connected and can even set serial communication errors for other modules, but since you get all (and only) serial errors relating to the EBTCM, it would sure seem to be real problem. The signal to release the parking brake ultimately comes from the RIM (rear integration module) but at some point appears to rely on a signal from the EBTCM over the serial communication line. The reason it will work after some length of time is likely because lacking communication from EBTCM, the system will begin to run on default settings (almost certainly without antilock brakes and traction control). These default settings also likely explain why the error codes do not reappear if you clear during a drive cycle, only coming back during the next drive cycle. This might make you think it's an intermittant problem when it is probably continuous. I've found the service manual (I have both print and on-line subscription) utterly invaluable for this car and a scan tool REALLY helps as well. The real thing (Tech II) is extremely expensive but the one I use (Auto Enginuity) is decent and affordable. The Palm/Pocket PC version however lacks many functions available in the PC version--something they don't mention at the website...I wound up with both versions. Link to comment Share on other sites More sharing options...
Jonny Wallin Posted November 18, 2008 Author Report Share Posted November 18, 2008 Hi Again! I have clean the connectors and make a good ground of the EBTCM box. Clear all codes and got for a short drive. After that the new codes was: U1255 Class 2 Initialization Error U1040 Loss of Class 2 Communications with ABS C1780 Loss of Steering Position Signal C1783 ICCS2 DL Left Output Short CKT to GND. What is "DL"?????? C1785 ICCS2 DL Right Output Short CKT to GND I hoped that someone have had the same failure and could give a standard answer. But life is´nt so easy. I dont have any OBII analyser to borrow. Maybe I have to leave the car to a workshop, but I don´t like that as an old car technian. Regards Jonny Wallin Link to comment Share on other sites More sharing options...
SwampeastMike Posted November 18, 2008 Report Share Posted November 18, 2008 Hi Again! I have clean the connectors and make a good ground of the EBTCM box. Clear all codes and got for a short drive. After that the new codes was: U1255 Class 2 Initialization Error U1040 Loss of Class 2 Communications with ABS C1780 Loss of Steering Position Signal C1783 ICCS2 DL Left Output Short CKT to GND. What is "DL"?????? C1785 ICCS2 DL Right Output Short CKT to GND I hoped that someone have had the same failure and could give a standard answer. But life is´nt so easy. I dont have any OBII analyser to borrow. Maybe I have to leave the car to a workshop, but I don´t like that as an old car technian. Regards Jonny Wallin "DL" stands for Datalink. The DL Left and Right outputs lead from the CVRSS (road sensing suspension) module to the EBTCM (brake/traction control module) and signal either "normal" or "rough road" to the EBTCM to "improve braking performance in rough road conditions". Given those errors, here's what seems an easy way to check for a bad EBTCM: 1) Disconnect the EBTCM connector (leave ground connected). 2) Turn ignition on with engine off. 3) Clear DTCs. 4) Wait at least 90 seconds. If C1783 and C1785 do NOT reappear, the EBTCM is bad. To replace the EBTCM remove the negative battery cable, lift the car (at least front end) remove the 3 bolts holding the EBTCM/BPMV assmebly retaining bracket. Remove the electrical connector. Remove the front insulator and insulator mounting bolt. Remove the four bolts holding the EBTCM to the BPMV and carefully remove the EBTCM by pulling forward--DO NOT PRY! Unfortunately, after replacing the EBTCM the MagnaSteer system has to be re-calibrated and you'll need a Tech II scan tool. Such involves little more than selecting the MagnaSteer unit and telling it to recalibrate, but I doubt anything but a Tech II can access. If the error code do reappear, it's some other problem (bad wiring?, bad road sensing suspension module?) but again, I'm really suspecting the EBTCM due to all of its serial communication errors. I have no idea if ignoring the problem will lead to more problems but I seriously doubt if the antilock brakes or traction control will work. When you press the Traction button on the center console do you get the "Traction Disabled" and "Traction Ready" messages from the DIC? Link to comment Share on other sites More sharing options...
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