300ZX (Z32) Performance / Technical Discussions related to Turbo charging, Supercharging, Engine, ECU, exhaust, and etc. performance enhancements and Techical related.

OBD! CODE 54: ECM and TCM not Communicating

Thread Tools
 
Search this Thread
 
Old 07-22-2008 | 01:32 PM
  #1  
bahumit12's Avatar
Thread Starter
Registered User
 
Joined: Mar 2006
Posts: 4
From: Hayward, CA
OBD! CODE 54: ECM and TCM not Communicating

I should have posted this to section, so I apologize for the mis -post inthe main forum. My friend hooked a hand-held diagnostic computer to my car and there were no codes from the the trans. Below is the short version of what I know.

1993 300ZX 2+2 NA AT stock

* Automatic trans will not shift to second except manually bu letting off the gas and then applying at the proper RPM's
* No codes from trans; solenoids are turning ON and OFF when appropriate
* The engine threw a CODE 54 (NISSAN OBD1) "ECM and TCM not Communicating"
* Looked under car and there is a wire that appears to have melted against the exhaust
* Trans is mechanically sound and is shifting, it's just the engine appears to not know what is going on: you can see on the computer that it shifts as high as 4th (cannot go faster than 40-50mph)

I did call a trans shop and they said to check fuses or the harness, but how?
So, my question is how can I repair this without taking it in and how much will it cost me -- how should I go about checking the ECM (I know it is behind the floor board on the passenger side). I have friend that can do the job, but he needs to know what to do.
OR

If there is a good Z Shop or transmission shop in the Bay Area (California) I should take it in to -- got quoted $85 just to look at the car based on all the above info.

FYI: I do have a dealer repair manual, so I can find out where everything is at.


Thanks for any information and help.
Old 07-22-2008 | 11:38 PM
  #2  
Riz Z Speed's Avatar
Administrative Brown Guy
 
Joined: Jun 2003
Posts: 5,406
From: Ontario, Canada
well, first things first, if u see something broken, fix it.
repair the wire that looks melted.
Next, DL the FSM and follow the Troubleshooting guide.
Push comes to shove u might need to replace some wires and/or the TCM.
Old 08-11-2008 | 03:14 PM
  #3  
bahumit12's Avatar
Thread Starter
Registered User
 
Joined: Mar 2006
Posts: 4
From: Hayward, CA
Safe Mode

I checked all the wiring and everything looked good: cleaned a few of the, rerouted the wiring and replaced the shielding and nothing has changed.

Now, my battery died a few months ago and I did replace it and I have read that can cause the ECU to go into safe mode, but the vehicle ran long enough to reset anything.

I had another mechanic tell me that the car might be in SAFE MODE since it is not throwing a CODE 55.

How do I go about reseting or clearing the code? There are currently no other codes being thrown. I have seen some information on other sites, butnothing that really explains anythin gin great deatail.

Thank you again for all the great responses.
Old 08-11-2008 | 03:22 PM
  #4  
JPerkins's Avatar
Registered User
 
Joined: Jun 2007
Posts: 505
From: oklahoma city, oklahoma
go to autozone and ask them to read your OBD1 codes. then ask them to clear them.

as for the safe mode deal, i don't know personally but i do know i've seen a thread about it here on z-driver. search and i'm sure you'll find it.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
97gtp
300ZX (Z32) Forums
2
07-31-2014 10:18 PM
97gtp
300ZX (Z32) Forums
2
07-12-2014 04:25 PM
jeff1986
300ZX (Z31) Performance / Technical
5
06-29-2013 10:56 AM
3riCJbOi
300ZX (Z32) Forums
2
09-23-2009 12:10 AM
cliftcrawford
300ZX (Z31) Performance / Technical
1
11-11-2006 03:05 PM



Quick Reply: OBD! CODE 54: ECM and TCM not Communicating



All times are GMT -7. The time now is 11:13 AM.