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Technical Lambda Sensors

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Technical Lambda Sensors

Tony123 said:
Does this wiring diagram make sense ?

Do you know what is wrong with the immobilizer ? i have a random wire just sticking up in the engine, looks like an earth but dont know what for.

How do i test the wires ?
Click to expand...

Without knowing what code is for each component, no. Though I can work out the 4 coils and injectors. Can't see the lambda sensors, or work out which is the evap valve.

Without more diagnostic data I can't say what's wrong with the keycode system, if there is a fault there at all (it doen't help that your code reader doesn't recognise a keycode fault, even though it's well known- only have to google the code to find a description within a few secs). It's not uncommon to get "U" error codes. Delete them and see if they return.
 
D4nny8oy said:
Without knowing what code is for each component, no. Though I can work out the 4 coils and injectors. Can't see the lambda sensors, or work out which is the evap valve.

Without more diagnostic data I can't say what's wrong with the keycode system, if there is a fault there at all (it doen't help that your code reader doesn't recognise a keycode fault, even though it's well known- only have to google the code to find a description within a few secs). It's not uncommon to get "U" error codes. Delete them and see if they return.
Click to expand...

Ive erased all codes and they are the ones which are sticking
 
Tony123 said:
Does this wiring diagram make sense ?

Do you know what is wrong with the immobilizer ? i have a random wire just sticking up in the engine, looks like an earth but dont know what for.

How do i test the wires ?
Click to expand...

The ECU has its own earth - black with a bolt-down ring on the end. Anywhere convenient will do for bolting it down.
 
I think you need to work on your bartering skills, I picked up 2 x Bosch Lambdas for £54 inc VAT each from Andrew Page.

I still think that was expensive.
 
D4nny8oy said:
It's not going to help a diagnosis with sensors unplugged. :doh:
Click to expand...

Lambdas are piezoelectric, they should generate a voltage even when unplugged assuming he is testing them with a voltmeter.
 
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Best way really is to use Fiat ECU Scan, you can graph their operation in there.

Failing that you can get an idea if they're working with a voltmeter, by hooking up to the grey and black wires (in a 4 wire sensor). Pre-cat should fluctuate between 0.1V and 0.9V, but it does this rapidly -- about once per second -- so is difficult but possible to measure using a voltmeter, post-cat should read constantly high close to 0.9V. You ought to allow the engine time to warm up to do this.

Oscilloscope is better again if you have one, wish I did.

Can use an ohm meter to test for heater element failure, if you have open circuit element has failed and would generate a trouble code, the two white wires are the heater element on a 4-wire Bosch lambda. Element should read somewhere in the region of 10-30 Ohms.

I'm not aware of how you would test a system featuring 3 Lambdas.
 
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Mr Wild said:
Lambdas are piezoelectric, they should generate a voltage even when unplugged assuming he is testing them with a voltmeter.
Click to expand...

I was referring to the list of error codes- in that leaving the sensors unplugged will generate false error codes in the ECU and waste our time trying to diagnose/find a common cause for all 3 being faulty. ;)
 
Does this help you with the wiring so you can test the sensors???
 

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WhiteSei said:
The software uses virtual serial ports via the USB system. New diagnostic cables should be USB.
Click to expand...

I know but that means buying one lol, the diagnostic I have is serial port, but I'm going to just change them anyway....

Is there any difference between pre and post cat sensors ?

Just took me car for a test spin round my estate, putting my foot down, there seemed to feel like a hesitation, this be the new belt wearing its way in ?

Also cleared the codes and without starting the enging just turning ignition, i got 3 fault codes, lambda sensor / Evap purge system fault / imobilizer fault.
after i got back to mine, i did a re scan and the second lambda sensor came back up, as well as another imobilizer fault.

anyone any ideas
 
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