Finished - OBD1 swap D14A3/4 complement
Posted: Sat Jan 30, 2010 8:00 am
I should complement the existing article with this:
There are 2 seperately monitored circuits for the (5V) sensors, the SG1 (+VCC1) and the SG2 (+VCC2).
The no. 1 circuit, is solely the MAP circuit which is the most important sensor for the ECU. If that one fails, engine certainly will perform less. Therefore its seperated. So effectively all 3 wires on the MAP sensor are, SG1, VCC1 and MAP (not sure about the order!).
The no. 2 circuit is all the rest. Inside the EJ9 wireloom, under the IM is a big splitter-plug. In here several circuits are split into multiple wires, I think IGP2, some grounds are there (PG, LG?), but definetly SG2 is split there. Its used for at least TPS and IAT, probably ECT as well. I recently puzzled this out for somebodies wireloom I had to repair. I cleaned the loom and in the process needed to pass this splitter plug were I noted the above.
So when having a heated lambda, I am 90% certain the splitter will have one additional SG2 split for it which misses in our EJ9 looms. Therefore, we have to construct our own splits. Personally I prefer splitting near the ECU so you can make sure the correct wire is splitted.