Performance & Maintenance Engine, forced induction, intakes, exhausts, torque converters, transmissions, etc.

Can't read OBDII CEL?

Thread Tools
 
Search this Thread
 
Old 02-12-09, 04:14 PM
  #1  
mattdev
Driver School Candidate
Thread Starter
 
mattdev's Avatar
 
Join Date: Feb 2009
Location: TX
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default Can't read OBDII CEL?

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.
Old 02-12-09, 05:18 PM
  #2  
audi2nr
Lexus Test Driver
iTrader: (1)
 
audi2nr's Avatar
 
Join Date: Apr 2004
Location: nowhereville
Posts: 1,307
Received 0 Likes on 0 Posts
Default

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?
Old 02-12-09, 06:50 PM
  #3  
Lexmex
Super Moderator
 
Lexmex's Avatar
 
Join Date: Apr 2004
Location: Miami, Florida
Posts: 17,240
Received 161 Likes on 137 Posts
Default

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.
Old 02-12-09, 06:56 PM
  #4  
HellFish
Lexus Test Driver
iTrader: (5)
 
HellFish's Avatar
 
Join Date: Aug 2007
Location: California
Posts: 1,051
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 02-12-09, 07:36 PM
  #5  
StiCk3
Lexus Champion
iTrader: (5)
 
StiCk3's Avatar
 
Join Date: Oct 2006
Location: IN
Posts: 1,892
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by audi2nr
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?
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...
Old 02-12-09, 09:20 PM
  #6  
mattdev
Driver School Candidate
Thread Starter
 
mattdev's Avatar
 
Join Date: Feb 2009
Location: TX
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default

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?
Old 02-13-09, 02:12 AM
  #7  
HellFish
Lexus Test Driver
iTrader: (5)
 
HellFish's Avatar
 
Join Date: Aug 2007
Location: California
Posts: 1,051
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 02-13-09, 10:35 AM
  #8  
mattdev
Driver School Candidate
Thread Starter
 
mattdev's Avatar
 
Join Date: Feb 2009
Location: TX
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 09-30-12, 01:31 PM
  #9  
karolek98
Driver School Candidate
 
karolek98's Avatar
 
Join Date: Sep 2012
Location: Poland
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
Default

figured out yet what to do? Got the same problem.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
2JZSC3oo
SC- 1st Gen (1992-2000)
3
10-29-12 09:14 PM
hoosier58
SC- 1st Gen (1992-2000)
2
01-14-12 01:23 PM
koukii
CL of Southern California
2
06-27-10 01:31 PM
clean
Performance & Maintenance
15
06-22-07 07:11 AM
additude
LS - 1st and 2nd Gen (1990-2000)
1
03-04-03 12:27 PM



Quick Reply: Can't read OBDII CEL?



All times are GMT -7. The time now is 05:05 AM.