Pages: [1]
Author Topic: ECU speed signal reception  (Read 7122 times)
diwasas
Newbie
*

Karma: +0/-0
Offline Offline

Posts: 15


« 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.
« Last Edit: April 25, 2016, 11:54:20 PM by diwasas » Logged
diagnosticator
Jr. Member
**

Karma: +2/-0
Offline Offline

Posts: 42


« Reply #1 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.
« Last Edit: July 21, 2016, 01:21:29 PM by diagnosticator » Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Online Online

Posts: 12270


WWW
« Reply #2 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.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
diagnosticator
Jr. Member
**

Karma: +2/-0
Offline Offline

Posts: 42


« Reply #3 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?
« Last Edit: July 21, 2016, 01:53:25 PM by diagnosticator » Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Online Online

Posts: 12270


WWW
« Reply #4 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.

Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
diagnosticator
Jr. Member
**

Karma: +2/-0
Offline Offline

Posts: 42


« Reply #5 on: July 21, 2016, 01:55:12 PM »

OK, I see where you are coming from now. Thanks!
« Last Edit: July 21, 2016, 01:58:18 PM by diagnosticator » Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Online Online

Posts: 12270


WWW
« Reply #6 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.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
Pages: [1]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.041 seconds with 17 queries. (Pretty URLs adds 0.013s, 0q)