Anyone know what the output voltage should be for the OBDii data line coming off the PCM (pin #59, on the top PCM connector aka "C1", purple wire). Mine's only outputting 0.25 volts. My wife's Mitsubishi's data line voltage at the OBDii port is outputting ~9v. I'm fairly certain mine should be somewhere between 3.5 & 7 volts. I checked all the usual things before digging into the PCM side of the electrical connections... I checked the 5v cigarette lighter fuse, bought a new one, used a fuse test light checker, etc. It's not the fuse. My radar detector & cell charger work out that port just fine.
The OBDii port... It's got 6 wires. #16, the power wire, outputs whatever the battery's getting without exception. When checked against the 2 grounds, #4 & #5, the readings are the same. Both engine grounds I redid & made sure the metal was nice & shiny. I even tried splicing a wire that ran all the way from the PCM to the OBD port for the data line, same issues. I took out & examined & checked for continuity the 2 pins at both ends for the data line (PCM pin coming out & OBD port pin). They both look good. On the OBD port, there is also a green wire. #14, "HS-CAN(-) : E&C. This one's getting 0.00 volts when I checked it with a multimeter. Does that sound right? There's a minus sign in the name leading me to believe it's a negative wire thus it shouldn't have any voltage. There's also a tan wire on the OBDii port, #9 in the diagram, "first UART." That one gets between 3.25 & 3.5v & it fluctuates.
I've narrowed it down to simply what the PCM is outputting for the data line. 0.25v does not sound right. On the web in a pretty techy explanation of the different OBD protocols, the author said that it should be between 3.5 & 7 volts and if not, "it's probably getting grounded somewhere." What does that mean? Is he referring to the long purple wire that runs all the way from the PCM to the OBD connector and that it could possibly have fused with another wire, etc. In my case, though, I'm checking the voltage from the pin out from the PCM and a strand of 2 inches of wire where I cut it to splice in a test wire.
My dash mounted Scan Gauge has been acting up for the past few months. It's slow to update data, freezes, & shuts off by itself. I've tried the unit in 2-3 other cars, works flawlessly. It's isolated to my car only.
Tried everything with the Scan Gauge II - changing it to Normal (vs. Fast), chose auto instead of VPW, changed the PIDs to supported instead of all, same sh1t.
