When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Super unknown condition 2002 Civic EX with a d17a1 bottom end and d17a2 head. P0141 with no ground to downstream sensor. I check the ECU and a14 and a25 wires are literally not in the harness and nowhere to be seen (not clipped, someone removed the actual female pin?). e2 and e6 are wired, but have been clipped and reconnected with a heat shrink. Question: if this car had an aftermarket ecu, is there a process that involves moving a14 and a25 somewhere? Those wires should come from the O2 sensor, to the #4 dash fuse, and then to a15 and a25 right? Anyone have experience with this and know where those wires might be?
That is not what my schematic shows at all, I don't show A14 or A25 being used for anything.
Pin E3 is connected to a shield around the white/red wire. It also runs to "L" at the bottom which just is a ground in the OBD2 connector. The Black/orange wire going to "D" at the bottom goes to fuse 1 in the under-dash fuse box.
That is not what my schematic shows at all, I don't show A14 or A25 being used for anything.
Pin E3 is connected to a shield around the white/red wire. It also runs to "L" at the bottom which just is a ground in the OBD2 connector. The Black/orange wire going to "D" at the bottom goes to fuse 1 in the under-dash fuse box.
Great! I checked for continuity and everything looks good from the o2 connector to the ecu connector. However, still receiving the p0141. It seems I can't get a ground at the black/white e6 at the ECU. If I disconnect the E connector and test the ground at pin 6, nothing. Time for a new ECU?
Pin E6 is the heater control, the PCM supplies the ground when it wants the O2 heater on. At the O2 connector do you also have battery power on the black/orange? Also, measure resistance across the black/orange and black/white but on the sensor side. This will verify the heater coil in the sensor is okay. I can't tell you for sure what you'll see here but it should be less than 10 ohms I imagine.
