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New Kvaser white paper discusses ways to maximise CAN’s efficiency in next generation vehicles


By using a Virtual CAN Bus, we separate the control task from other tasks. The distributed embedded control system can be developed using standard CAN Controllers and transceivers in a traditional way with well proven tools.

Other tasks such as encryption, transmitter authentication, re-flashing, etc. can be developed by experts in these fields and carried out by using other protocols. With modern technology, the different tasks can run in parallel and simultaneously communicate on the same physical layer.

It is a great advantage to separate the control problems from other problems. The control problem can be solved once and for all by the control experts and other problems by experts in their respective technology fields.

 

Details here......

 

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CAN Test Box

can test box

 

Continuing with our mission to make vehicle diagnostics easier and faster…the new CAN Test Box gives you easy access to the 16 pins of the diagnostic connector that is fitted to all modern vehicles. Depending on the configuration of the vehicle, this may allow you to check power, ground and CAN Bus signal quality. With the test leads supplied you can connect your PicoScope lab scope to the CAN Test Box to monitor signals such as the CAN High and Low. More.....

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Automotive Scope Users


Pico Automotive Scope software now sports a new Waveform Library browser.
Must own PicoScope to view.
See details here

 

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 Case Study - Mercedes E240 Does not Start


Mercedes E240
Picoscope Logo
AuthorMike
Fri Jan 13, 2012 1:08 pm

Details: Andy Cape - Cape Auto Diagnostics


1. Vehicle Details:

  • 1998 Mercedes E240
  • W210
  • Engine No M112


2. The Problems
Engine does not start!

3. Investigation with Scan Tool
No current faults logged in system (ME2-SFI), however a condition (live data) was stored: Safety fuel shut off is ON.


4. Investigation with PicoScope

Somewhere deep in the Mercedes Manuals I found a hint that a SAFETY Fuel Shut OFF is initiated by the ECU when there is something wrong with the throttle body. I then went ahead and carried out some checks. Firstly, to check the pedal position potentiometer is working correctly; both sensors can be seen below standard blue and emergency limp home sensor red.


Position Potentiometer both Signal ok.png

Position Potentiometer both Signal ok.psdata
(1.39 MiB) Downloaded 72 times

Next, I checked the throttle body end stop switches. Both seem to be correct (S1 & S2) for CTP (Closed Throttle Position) and WOT (Wide Open Throttle). One operates at 4.2 V the other at 0.8 V. I am not sure if the values are correct but I can tell it is switching at least.

S1 & S2 Ignition off and on.png

S1 & S2 Ignition off and on.psdata
(1.07 MiB) Downloaded 31 times

The throttle valve position potentiometer output remains constant at 4.2 V (blue), with no change during re-programming or at ignition ON. I can hear the throttle motor working but the position is frozen at almost maximum. The Motor voltage (12 V green) is switched off at the moment I want to start the car or push the gas pedal. This is due to a safety fuel shut off being activated by the ECU. Red is showing the GND to body GND.

No engine start but as soon gas pedal is pressed - motor 12V shut off.png

No engine start but as soon gas pedal is pressed - motor 12V shut off.psdata
(1.24 MiB) Downloaded 90 times

5. Result

After removing and inspecting the throttle body it was clear the throttle valve had heavy carbon deposits, causing the throttle valve flap to be stuck in the open position. The ECU then switched to a safety mode "fuel shut off".

After cleaning and re-programming (adaption reset) the car started without problems and the idle speed was fine.

Case Study Information
Detail: Andy Cape - Cape Auto Diagnostics

Author: Mike Valentine Mike Valentine
Assistant Technical Author - Pico Technology
 
 
 
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