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No Communication with PCM

1524 Views 11 Replies 5 Participants Last post by  jtrealty
1999 Esprit 3.5L Check engine light on running rough. Have tried 4 different generic scanners (no Tech 1) and all say no communication. Connector does have power and i do not see any signs of wiring issues to PCM. Has anyone had success using a generic scanner to read codes on this year and model?
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Ignition on? Tried both connectors? One in rear boot, one under pax side dash
key on and have tried both connectors
Go to autozone buy the ACTRON CP9135
OR TRY THEIR ACTRON FIRST AND SEE IF YOU HAVE FAULT IN THE OBD WIRING.
Autozone will let you use their scanner for free.
Not all scanners work. Even if they do, not all can read all of the codes, some are special to Lotus. The only one I know that works besides a Tech 1 is OBD-2.com on a PC. To compound the confusion there are communication issues that were corrected with the HTU (High Torque Upgrade) firmware reflash. If your ECU does not have the HTU it is worth getting for this and other reasons. There would be a sticker or magic marker indicating such on the case of your ECU. If you don't have it, you have to send your ECU to Lotus USA to get it. In the meantime maybe you can go to AutoZone or someplace where they will pull codes for free. Maybe with a different scanner they will be able to pull the codes. If you do get the codes out I suggest you clear them and see what comes back. Your ECU may be filled with a lot of codes that are not the current problem. Once you have the codes we can help you figure out what the root cause is. In the meantime use up the fuel and put some fresh stuff in the tank. One common problem is if the O2 sensors (Pre and Post) get mixed up so verify they are correct. Make sure the battery is fully charged. Make sure you have the correct gas cap and the neck is not deformed or bent from someone filling the tank. Do a visual inspection of all of the hoses. Check they are all connected and not cracked.
David Teitelbaum
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Just tried the ACTRON CP9135, it got further then the rest. It said downloading information but before it gave the results the scanner shut down and re booted. Tried multiple times with same results. Have a Tech 1 from a friend being sent to me from out of town, will try that. Also think i will throw O2's at it because thats how it is acting.
oh well, could be something to do with your upgrade ecu. i used actron cp9135 in my two Esprit V8. My friend occasionally use my actron too.
Just tried the ACTRON CP9135, it got further then the rest. It said downloading information but before it gave the results the scanner shut down and re booted. Tried multiple times with same results. Have a Tech 1 from a friend being sent to me from out of town, will try that. Also think i will throw O2's at it because thats how it is acting.
Do not start "throwing" parts at the problem. All that does is introduce more variables. You could have a bad new part or you could mix things up or maybe the sensors you use just aren't the correct ones. It is also not inexpensive, there are four of them.
David Teitelbaum
The PC software is what I use. Works pretty well. You'll need a USB to OBD adapter cable. I got one from amazon....

[ame]http://www.amazon.com/gp/product/B001MT0XPK/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1[/ame]
Does Freescan work on the V8, or is there a different PC software?
Here:

Free V8 OBDII Scan Tool - ECU/OBDII - The Lotus Forums

Not having used freescan, I don't know how it compares
Here:

Free V8 OBDII Scan Tool - ECU/OBDII - The Lotus Forums

Not having used freescan, I don't know how it compares
Freescan won't work on the V-8's. It is for the 4 bangers. And even with that you still have to get a cable. Watch out for some of the older software, it was created to use a serial port on a older PC. Since that is not common anymore you need a convertor to get into a USB port and the older stuff has timing issues and doesn't always work with every PC. Then there is the Windows version. If you are not running XP some of the older software has problems with the newer Windows. If you are trying to do this "on the cheap" and get the freeware stuff there is no tech support when it doesn't work. You are on your own to try to figure it out and there are a lot of ways it won't work.
David Teitelbaum
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