Author Topic: ECU pin assignments for O2 sensor  (Read 9564 times)

0 Members and 1 Guest are viewing this topic.

1 Thump

  • Grand Gearhead
  • *****
  • Posts: 1,563
  • Karma: 0
Reply #15 on: January 13, 2013, 04:40:07 pm
Is this board awesome or what ?


gremlin

  • Grand Gearhead
  • *****
  • Posts: 1,873
  • Karma: 0
  • "Do one thing each day that scares you"
Reply #16 on: January 13, 2013, 06:13:47 pm
And on the lower left: a diode?  Why doesn't the other end connect to anything?  The ECU pin is labeled "SG"...  ??

That circuit is the sensor ground circuit.

It's main function is to provide a common reference for reading the sensor(s) output voltage(s)/current(s)

The actual frame ground of a vehicle is noisy as hell, this circuit acts as a quiet local ground field that collects all the sensors and brings them to the ECU, before connecting them to the chassis.
1996 Trophy 1200
2009 Hyosung GV250
2011 RE B5


singhg5

  • Grand Gearhead
  • *****
  • Posts: 2,785
  • Karma: 0
Reply #17 on: January 15, 2013, 04:41:33 am
In the previous photo of ECU circuit, the inverted triangle looked like an electrical symbol for a diode and I had penciled as such. 

Thanks to JVS and Gremlin who corrected that to be 'Surface Sensor Ground Circuit' - though I do not fully understand that thing.

Below is the revised version of the ECU circuit - hopefully the labelling is more readable and correct.
 
Surface ground should read SENSOR ground in the diagram, prepared by my tired brain at midnight on the topic I know little  ;)
« Last Edit: January 16, 2013, 03:31:06 am by singhg5 »
1970's Jawa /  Yezdi
2006 Honda Nighthawk
2009 Royal Enfield Black G5


gremlin

  • Grand Gearhead
  • *****
  • Posts: 1,873
  • Karma: 0
  • "Do one thing each day that scares you"
Reply #18 on: January 15, 2013, 07:34:54 pm
SENSOR ground  (aka sensor return) or signal ground.
1996 Trophy 1200
2009 Hyosung GV250
2011 RE B5


singhg5

  • Grand Gearhead
  • *****
  • Posts: 2,785
  • Karma: 0
Reply #19 on: January 16, 2013, 03:18:44 am
SENSOR ground  (aka sensor return) or signal ground.

'Sensor Ground' it is Now ! In its 3rd revision  :).

While we are at this topic,  can you explain a bit more. 

If the 'sensor ground' wire is not attached to frame, where is it attached ? Is it the ECU pin 24 that act as 'sensor ground' ? If so, how does it act as ground ?

Also, it seems that 4 sensors - throttle position sensor, air manifold pressure sensor, engine temperature sensor and O2 sensor - are part of this 'sensor ground circuit'. 

How does this grounding provide common reference for sensor output and perhaps reduce background electrical 'noise' or variation from sensor to sensor for more accurate reading ?
 
« Last Edit: January 16, 2013, 04:56:30 am by singhg5 »
1970's Jawa /  Yezdi
2006 Honda Nighthawk
2009 Royal Enfield Black G5


gremlin

  • Grand Gearhead
  • *****
  • Posts: 1,873
  • Karma: 0
  • "Do one thing each day that scares you"
Reply #20 on: January 16, 2013, 01:25:26 pm
First, let me preface this discussion by saying that I KNOW NOTHING specific to the bullet.  The knowledge I am drawing on for this discussion is standard engineering school fodder.

:Having said that:

The signal ground is connect to the frame ground, however, that connection is via a relatively high inductance path.  - Imagine how Lake Superior is connected to the Atlantic Ocean......   generally speaking, the surface disturbances of the Ocean do not find their way up the chain to Lake Superior - However - they are interconnected !
1996 Trophy 1200
2009 Hyosung GV250
2011 RE B5


GreenMachine

  • Grand Gearhead
  • *****
  • Posts: 3,155
  • Karma: 0
Reply #21 on: January 16, 2013, 03:56:22 pm
Gremlin: As u r aware, the best ground potential is earth and in some cases that requires a bit of engineering, chemicals, using a megger, etc to reach a given potential to satisfy the  requirement needed. Grounds are a antenna and radiate if the end point isn't tied to a lesser potential (chassis) . .I would think a standard motorcycle or auto has a bit of noise when viewing the Grounding with a anaylzer...Either way, it's the standard that's been in play for quite a while. It works, cost effective and fairly easy to fix.    Excessive vibration doesn't help our cause.
..I did enjoy your analogy by the way..GM
Oh Magoo you done it again


Dave1

  • Grease Monkey
  • ****
  • Posts: 297
  • Karma: 0
Reply #22 on: April 25, 2021, 05:11:59 pm
Hi guys,

Sorry to drag up an old thread, but this is relevant to the issue I am having. If the black wire is ground/negative from the O2 sensor to the male connector, and the wire opposite in the female connector is white. Should I to test the white wire is ok set my amp meter to 12v DC and then ground my multimeter to negative pole on the battery?

Or is there another way I can check the power?

I'm trying to figure out if I need a new O2 sensor or if my O2 sensor isn't getting power. Engine warning light is on, and tells me its the Oxygen sensor heater or circuit ( Code 45 ) on MIL light.



TrianglePete

  • Bulleteer
  • ***
  • Posts: 220
  • Karma: 1
  • U.S. Spec RE parts & THE FIN intake.
Reply #23 on: April 25, 2021, 05:31:54 pm
Gremlin: As u r aware, the best ground potential is earth and in some cases that requires a bit of engineering, chemicals, using a megger, etc to reach a given potential to satisfy the  requirement needed. Grounds are a antenna and radiate if the end point isn't tied to a lesser potential (chassis) . .I would think a standard motorcycle or auto has a bit of noise when viewing the Grounding with a anaylzer...Either way, it's the standard that's been in play for quite a while. It works, cost effective and fairly easy to fix.    Excessive vibration doesn't help our cause.
..I did enjoy your analogy by the way..GM

Thank you Ace for starting this thread...   

We all need to learn more about the ECU and sensors

Thank you Guys


viczena

  • Grand Gearhead
  • *****
  • Posts: 753
  • Karma: 1
Reply #24 on: April 25, 2021, 07:18:29 pm
Depends on what power you want to measure. The heating is directly connected frame ground. There you can use any point on the frame. The signal ground is also connected to frame, but ist is the ground for the 5V reference the EFI delivers for the sensors. Its available current is limited (110mA). So you better find a connector where you can get this ground from copper.
www.enfieldtech.de
Harley CVO EGlide, Boss Hoss 502, BMW 1200 RT, Harley Panhead , Harley Davidson &Marlboro Man Bike BD2, Royal Enfield Trials, KTM EXC 500. And some more.


TrianglePete

  • Bulleteer
  • ***
  • Posts: 220
  • Karma: 1
  • U.S. Spec RE parts & THE FIN intake.
Reply #25 on: April 25, 2021, 07:49:07 pm
As long as we are discussing Grounds   and their quality.

Everyone should upgrade their Battery to engine Ground wire.  Please...

14 gauge cheap is not enough to keep everything Happy. 

Lets not stop here...  We could go through all the sensors and how they work or malfunction .

This is GREAT !


Bert Remington

  • Grease Monkey
  • ****
  • Posts: 440
  • Karma: 0
Reply #26 on: September 05, 2021, 12:46:43 am
singhg5 -- your excellent diagram shows three grounds:

PG -- Power Ground which carries higher currents for actuators, some sensor power and the ECU
LG -- Logic Ground which carries low currents for control signals
SG -- Sensor Ground/Signal Ground which carries very low currents for analog sensor signals

All three grounds should be carried to a common ground point (which as I recall was a 10mm screw under the seat).

The sensor ground MUST have its own separate wire to the common ground point.  Otherwise there is the risk of noise insertion from the power ground currents.

Proper grounding because critical with the introduction of electronic engine controls, both actuators (eg, fuel injector) and sensor (eg, throttle position).  And at the same time connector weather-tightness became critical, both for the facing pins themselves but also for the wires coming into the connector shell.  And piercing wire insulation for voltage/continuity testing became a source of future troubles as moisture entered and traveled to the pin-to-pin interface.  Electrical tape provides protection but not a seal.  You need self-sealing or liquid tape or RTV.  And better than tapping into an existing ground wire is running it all the way to the common ground point.

Let me know if you'd like the abbreviations decoded.
2016 RE Classic 500 CA version Fair-Weather Mountain Bike
2014 Can-Am Spyder RT-S SE6 Freeway Commuter Pod


AzCal Retred

  • Chennai Wrencher
  • Grand Gearhead
  • *****
  • Posts: 7,154
  • Karma: 0
  • a journey of a thousand li starts under one's feet
Reply #27 on: September 05, 2021, 05:48:34 am
Self sealing insulating neoprene liquid cement like Starbrite is pretty bulletproof. RTV & silicones in general release acetic acid (vinegar) when curing which is hard on copper connections.
A trifecta of Pre-Unit Bullets: a Red Deluxe 500, a Green Standard 500, and a Black ES 350.


Guaire

  • Grand Gearhead
  • *****
  • Posts: 1,981
  • Karma: 0
Reply #28 on: September 10, 2021, 02:13:07 pm
Hi guys,

Sorry to drag up an old thread, but this is relevant to the issue I am having. If the black wire is ground/negative from the O2 sensor to the male connector, and the wire opposite in the female connector is white. Should I to test the white wire is ok set my amp meter to 12v DC and then ground my multimeter to negative pole on the battery?

Or is there another way I can check the power?

I'm trying to figure out if I need a new O2 sensor or if my O2 sensor isn't getting power. Engine warning light is on, and tells me its the Oxygen sensor heater or circuit ( Code 45 ) on MIL light.

Hi Dave1 - This circuit tester lets you probe any wire. It will tell you ground or positive. It will also tell you what voltage is on the wire. I have found mine to be very helpful and worthwhile.
https://www.powerprobetek.com/product/power-probe-3/
ACE Motors - sales & administration