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Title: ECU speed signal reception Post by: diwasas on April 25, 2016, 11:52:34 PM Hi,
I have Audi a4 b6 1.9tdi 130hp 2002y. ECU (EDC15p+) not receiving vehicle speed signal (VCDS: engine block, channel 006, and i think 23 or 33 can't remember now), but detects RPM. For example: Instrument Cluster or Climate control unit receiving vehicle speed without problem. As far as I know, ECU receiving speed signal from Instrument cluster, so does it come through separate wire, or through CAN? Can not find any good wiring diagram for this. Title: Re: ECU speed signal reception Post by: diagnosticator on July 21, 2016, 01:08:50 PM Hi, I have Audi a4 b6 1.9tdi 130hp 2002y. ECU (EDC15p+) not receiving vehicle speed signal (VCDS: engine block, channel 006, and i think 23 or 33 can't remember now), but detects RPM. For example: Instrument Cluster or Climate control unit receiving vehicle speed without problem. As far as I know, ECU receiving speed signal from Instrument cluster, so does it come through separate wire, or through CAN? Can not find any good wiring diagram for this. You are asking about 2 different speed data. First, there is engine RPM, the ECU is the source for that data and is sent to other controllers on the CAN buss. Vehicle road speed data originates from a speed sensor installed in the transmission (only for '02 in NA,) sent to other controllers via dedicated VSS buss circuit, or from the ABS via CAN from '01 only for Euro models. The instrument cluster receives road speed from the ABS for display on the speedometer. The IC receives engine RPM from the ECU via CAN and displays that data on the tachometer. Title: Re: ECU speed signal reception Post by: nyet on July 21, 2016, 01:21:29 PM diag: i assume he's referring to vfzg, which can come from CAN vamsr_w (ABS), vfzgkb_w (combi), or direct from speed sensor, depending on CWGGVFZG
GGVFZG in the FR: Quote Die Konfiguration erfolgt ¨uber das Codewort CWGGVFZG. Ist Bit 0 in CWGGVFZG gesetzt, wird die Geschwindigkeit aus der CAN-Botschaft Kombi 1 (vfzgkb_w) verwendet. Das gleiche gilt, wenn Bit 2 in CWGGVFZG gesetzt ist und B_cankbi = 1 den Empfang der CAN-Botschaft vom Kombi anzeigt. Wird vfzgkb_w nicht verwendet und ist Bit 1 in CWGGVFZG gesetzt, wird statt dessen die Geschwindigkeit aus CANBotschaft Bremse 1 (vamsr_w) verwendet. Andernfalls wird das Hardwaresignal ausgewertet. Title: Re: ECU speed signal reception Post by: diagnosticator on July 21, 2016, 01:35:19 PM The vehicle road speed and engine RPM associated with the internal ECU variable parameters defined by the parameter IDs you mentioned, are not available for observing via VCDS, being the reference from the OP, because I am not informed sufficiently yet and It did not occur to me that the inquiry was associated the the internal variables you mentioned based on the context of the question wording. Maybe I am oversimplifying the intent of the OP. If that is the case please explain why you inferred the context of the question the way you stated. Not a challenge, only a request for my learning task.
Google translation of FR description you posted: "The configuration is done via the code word CWGGVFZG. If Bit 0 is set in CWGGVFZG, the speed of the CAN message is Kombi 1 (vfzgkb_w) used. The same applies when bit 2 is set in CWGGVFZG and B_cankbi = 1 receiving the CAN message indicating the Combined. If vfzgkb_w not used and bit 1 is set in CWGGVFZG, is instead the speed of CANBotschaft Brake 1 (vamsr_w) used. Otherwise, the hardware signal is evaluated." I do not understand from the FR description, what exactly is being configured. What am I missing from the OP's post associating the situation described in the FR? Title: Re: ECU speed signal reception Post by: nyet on July 21, 2016, 01:43:22 PM Dunno. I don't use VCDS for logging, but ME7Logger can log vfzg directly.
I assumed VCDS blocks 5 and 36 show vfzg (or a very proximate variable based on GGVFZG) He specifically asked why his *ECU* might not be reading the speed signal, not the combi, and not RPM. Title: Re: ECU speed signal reception Post by: diagnosticator on July 21, 2016, 01:55:12 PM OK, I see where you are coming from now. Thanks!
Title: Re: ECU speed signal reception Post by: nyet on July 21, 2016, 01:57:59 PM BTW to clarify, that is from the ME7 FR. I do not have an EDC15 FR, so I have no idea if the information I posted is relevant.
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