96dxcrapbox

my 96 dx has the code po135 heater circuit. from the searching i have done here i need to test the pin a6 at the computer (thanks ron)
can someone tell me which wire is A six? fuse 15 tests good
i think it is on the blue plug at the ecm.

96dxcrapbox

204 views not one answer?

Former User

Actually, what you need to do first is:

1) Test whether the O2 sensor wire harness plug gets voltage on the Blk/Yel wire terminal with the key in ON(II).
2) Measure the resistance across the two heater element wires of the sensor connector.

96dxcrapbox

thanks

96dxcrapbox

ok here is how i fixed my issue
there was no voltage at the pin a6 @ the computer, so i made a jumper wire with a few t taps and hijacked voltage from pinout a5 which is the secondary o2 sensor heater circuit.
no more check engine light.

cheaper than a new ecu.

Former User

A6 and A5 do not provide voltage. They supply ground to the O2 sensor heater elements. Jerry rigging wires is a dangerous proposition.

96dxcrapbox

are you sure ? on my car a5 most certainly has voltage. the check engine light is now off
i also scanned my car with my vantage and there is no pending codes and my ecu still communicates properly.
i will check it again in the am.

edit ........whats the worst that could happen ? i fry my computer? have you seen the pictures of my pos??check my garage lmao
as long as the light stays off long enough for me to pass smog i am good.

Former User

Yes, I'm sure. The O2 sensor heater elements receive constant voltage via fuse 15 with the key in ON(II). This allows the to ECU turn the heater element on and off by either supplying or removing ground at A5 or A6. What you have done is wired the primary heater element to the ground for the secondary heater element, resulting in loss of separate control for primary O2 sensor.

96dxcrapbox

i was thinking that there would be a control issue as i jumped the wires. at this point the light is off i am going to see if the thing will pass smog like this. i will post up my numbers.

96dxcrapbox

so what you are saying is that the monitoring voltages will be the same? please explain this loss of control.

96dxcrapbox

with all due respect i think you are wrong here. on my car heater voltage is coming out of a5 for the secondary sensor all i have done is activated both heater circuits.
the reference voltages are still separate

Former User

No sir. Without a doubt, voltage comes from fuse 15 for both O2 sensors. A5 and A6 are grounds. Just look at the circuit diagram I posted.