Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet with the UCE engine => Topic started by: ace.cafe on January 12, 2013, 12:42:02 pm
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Can anyone tell me what pins on the ECU are assigned to to O2 sensor for each wire from the O2 sensor that might go to the ECU?
Or if that's difficult, perhaps a couple of snapshots that show the connector with the wire color codes that go to the O2 sensor?
I'm working on getting this ECU under control.
Thanks in advance.
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ECU pin number 7 and 17 are connected to Oxygen Sensor.
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ECU pin number 7 and 17 are connected to Oxygen Sensor.
Thank you very much Mr Singh!
I trust you are well?
Would it be too much to ask if you know which color wire went to each pin?
This would be of great help.
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Thank you very much Mr Singh!
I trust you are well?
Would it be too much to ask if you know which color wire went to each pin?
This would be of great help.
Doing OK. Thanks.
I will try to find that out, when I go to see my bike which is in storage room for winter.
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ECU pin number 7 and 17 are connected to Oxygen Sensor.
Maybe not relevant to your needs, but...
7 and 17 are unique to the 02 sensor. My diagram also shows two other wires from the 02 sensor. One joins other sensors to connect to pin 24 (a black wire, according to the diagram). The other looks like it gets power from the battery, and also connects to pin 1. I'm guessing these are power and ground?
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Maybe not relevant to your needs, but...
7 and 17 are unique to the 02 sensor. My diagram also shows two other wires from the 02 sensor. One joins other sensors to connect to pin 24 (a black wire, according to the diagram). The other looks like it gets power from the battery, and also connects to pin 1. I'm guessing these are power and ground?
Matt,
VERY relevant.
I needed that too.
Thank you!
You guys are AWESOME!
You have no idea how much that helped me out!
And this will make some progress toward the goal!
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Here is a picture of the wires from the oxygen sensor.
It has four wires - one white and one black for power and ground ?? Perhaps 2 sensor wires are white and grey ?? COLOR CODING SUBJECT TO VERIFICATION AND CONFIRMATION.
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Here is a picture of the wires from the oxygen sensor.
It has four wires - one white and one black for power and ground, respectively. The 2 sensor wires are white and grey.
Awesome!
Thank you, SinghG5!
I would surmise from that photo that the two white wires are the heater for the O2 sensor, and the black and gray wires are for the sensor itself.
Very helpful info.
Thank you for your help, SinghG5 !
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Assuming the wire color stays the same on both sides of the harness connector(s)? I wish I could get to my bike to check out the rest of the wiring, but everything is packed away...
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Awesome!
Thank you, SinghG5!
I would surmise from that photo that the two white wires are the heater for the O2 sensor, and the black and gray wires are for the sensor itself.
Very helpful info.
Thank you for your help, SinghG5 !
After I had posted, I remembered that RE wiring color scheme does not always match with the circuit diagram.
The wires can be different colors at the coupler, on their way from one place to the other.
It is advisable to confirm which wire is which by actual testing.
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It's always good to check that the wiring goes where it should.
However, it is a common thing with O2 sensors that the wires which are of the same color go to the heater.
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Tom, Following is the ECU pin configuration for its sensors - in case you need it in future.
NOTE - ONE OF THE PINS LABELLING HAS BEEN CORRECTED IN LATER VERSION OF THIS PHOTO - SEE A FEW POSTS BELOW THIS ONE.
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What the heck is the"k-line" device? It's got +12v from the battery, ground, and one wire into the ECU...
And on the lower left: a diode? Why doesn't the other end connect to anything? The ECU pin is labeled "SG"... ??
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According to http://www.team-bhp.com/forum/motorbikes/73998-royal-enfield-500-classic-thread-62.html#post2157100
K-line = 'the connector used for connecting the ECU to computer or code reader.'
And according to the legend provided in the wiring diagram, that SG triangle is a 'Sensor ground', not a diode? ??? Not sure. Gremlin will help us here :D
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I wonder which one is the wire you ground to display the blinking fault codes?
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Is this board awesome or what ?
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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.
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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 ;).
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SENSOR ground (aka sensor return) or signal ground.
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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 ?
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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 !
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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
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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.
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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
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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.
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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 !
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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.
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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.
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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/