Hello all,


Some help please,


I want to cancel the lambda sensors, just two of them downstream on my car, through simulator(s) unit.
I use the XJ SEDAN 1995 electrical guide, pages for AJ16 NA ROW, where my car belongs.


The simulator unit(s) require three connections:

1. sensor ground wire, which I locate, for both sensors, at the wiring of pin PI105-8
2. sensor signal wire, which I locate at the wiring of pins PI105-16 and PI105-18
3. sensors 12V source, which I can not locate.

Following the manual I have two choices:

1. common for both sensors heaters, wiring to pin PI104-4
2. common to both sensor heaters, wiring coming from RH ENGINE BAY FUSE BOX, through a 10A fuse, marked as RS6, colored WG.

Alternative, since I'm going to install the simulators at the ECU area, I'm looking for 12V source at this area, looking at the manual, fig.04.2, I can locate as "active B+ battery voltage" the wiring to pins:
PI104-34, marked as O-output
PI105-2, marked as I-input and
PI105-24, marked as O-output


How to proceed ?


Any help is very appreciated,
Thank you,
Panagiotis

 

Hi panagiotis,

If I read the schematic correctly, the ignition-switched 12V for the lambda sensor heaters arrives on the White wires with Green tracer lines (WG), from Fuse 14 (10A) in the RH Engine Bay Fuse Box.

The other side of the heaters (their earth/ground path) connects to terminal PI104-4 of the ECM via the Blue wire with Pink tracer line (UK).

Hopefully someone with better eyesight than mine will either confirm or correct me!

Cheers,

Don

 

Hi Don,


Yes, this is the wiring to the sensor heaters.
So what I understand is to look for the 12V sensors supply at the WG cable, which I'm going to check today, should give me 12V, if I probe check the wire with any ground, when the ignition is "on", correct ?


Panagiotis

 

Yes, I believe you should be able to measure 12V from the WG wires to any good ground, since it is ultimately ignition-switched battery voltage you are measuring.

Please keep us informed!

Cheers,

Don