Have a '97 SC300. And can't get the OBDII to read for the life of me.

I have an ELM323 OBDII scanner that I use as a logger for my DSM. It uses ISO protocol. I can't get it to connect, the light on the cable is solid red, and will not turn green, no matter what order I plug in the cable (laptop, port, car on/off, etc.) On the computer, using several readers, it always says it can't connect and asks if they ignition is on.

I can't figure out why, I already checked the OBDII fuse, and it looks perfect. Does the '97 indeed use ISO, and support ELM323, or do I need ELM327?

Secondly: What is the diagnostic port under the hood for, it looks like OBDI, and there is a round port right next to the OBDII port, what's that for?

P.S. I hate dealing w/ autozone, I'd prefer to bypass them, lol.

 

the one under the hood are pinout's for some sensors. so you can check the sensors without going to the specific connector and tapping the wires. autozone sucks, but they do it for free, so maybe its worth a shot. maybe you have a wiring issue @ the obd connector?

 

I have sometimes had issue with my OBD2 scanner and my girlfriend's Expedition, but with my RX300 and other vehicles no issue. I have hunch it's related to electrical issues, perhaps grounding, because she has a strong enough battery, fuses are okay, but sometimes I see from electrical gremlins (displays going on and off) and it's pretty rusted on some of the grounds.

 

you are connecting the OBDII connector while the key is on and engine off right? ive seen alot of people do that. not trying to imply anything here. check pin 16 if there is power. if youre lookin at it taper side down, its the one in the far right.

 

Autozone is okay for reading codes, but it doesn't display readouts of sensors and such which would give you a better picture of inside the engine and what possibly could be wrong. Also after pulling a code sometimes the Autozone guy will try to sell you a part that may or may not fix the problem. the thing is that these guys are getting paid $8/hour selling parts and reading codes as opposed to a tech who gets paid $80/hour flat rate and does the job right most the time.

this is why we commonly refer to Autozone as the Twilight Zone...

 

I'll give autozone a shot, I thought maybe I was missing something. I know it's just a glorified toyota and all. (not an insult, lol, try driving a DSM as a daily). I thought maybe they had a raindance that accompanied a diagnosis, like German cars. Also wasn't sure if what I read was accurate or not, I know post '95 is supposed to be OBDII, but not sure if the interface is correct.

And that round "diagnosis" port is the same as the one under the hood (next to timing belt cover) just another access?

I'll pull out the voltometer and test pin 16. However, the light on the cable will stay on even when disconnected from laptop (but plugged in to the OBD port). Wouldn't that mean its getting power?

 

its getting power but its not getting the signal from the ecu. thats a constant 12v source i believe. so make sure the key is on, you know with all the dummy lights on and yeah.

 

You sound like my OBDII software "is the key in the ON position". Haha, no worries, I'll quadruple check everything. I didn't test any wiring or connections yesterday since I thought it was a protocol problem, but I've learned more about OBDII in 12hrs than I ever knew existed...

I'll keep you guys in the know, as long as you do the same, haha.

 

figured out yet what to do? Got the same problem.