Go Back   Cadillac Forum - Enthusiast forums for Cadillac Owners > General Technical Section > General Tech
Sign in using an external account
Register Forgot Password?
Search

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 03-01-2010, 03:09 PM
Junior Member
 
Join Date: Mar 2010
Posts: 2
Default 1990 Deville BCM/ECM communications problems!

We've got a 1990 Deville that continues to throw an F32 code. We've replaced the ECM and the BCM as last resorts. We bypassed the pass key module because we haven't been able to find a replacment module. The prom chip was reflashed to work without the anti theft system and that's when the trouble started.

The first time the car is started after the ECM is installed, everything works great. no codes, no lights, runs great, no problems.

The second or third time you start the car afterwards it throws codes, turns on CK engine and SVC vehicle lights, runs in limp mode and there is no communication between the BCM and ECM. we've checked the wiring between the two computers and it is okay. If you try to erase the code(s) they come back within 1 second.

At this point we're at a total loss of things to try and do. If anyone can lend some advice to help us out it'd be greatly appreciated!

Thanks,
Kurt S.
Reply With Quote
  #2  
Old 03-01-2010, 03:37 PM
stomper's Avatar
Tech Certified Members
 
Join Date: Jun 2007
Posts: 2,704
Default

pretty close to 100% of electronics issues are related to e-ghosts.
have you read our FAQ thread on e-ghosts?


Quote:
Originally Posted by HotRodGMC68 View Post
We've got a 1990 Deville that continues to throw an F32 code. We've replaced the ECM and the BCM as last resorts. We bypassed the pass key module because we haven't been able to find a replacment module. The prom chip was reflashed to work without the anti theft system and that's when the trouble started.

The first time the car is started after the ECM is installed, everything works great. no codes, no lights, runs great, no problems.

The second or third time you start the car afterwards it throws codes, turns on CK engine and SVC vehicle lights, runs in limp mode and there is no communication between the BCM and ECM. we've checked the wiring between the two computers and it is okay. If you try to erase the code(s) they come back within 1 second.

At this point we're at a total loss of things to try and do. If anyone can lend some advice to help us out it'd be greatly appreciated!

Thanks,
Kurt S.
__________________
"If you're going through hell, keep going"
~ Winston Churchill


Reply With Quote
  #3  
Old 03-03-2010, 11:20 PM
Member
 
Join Date: Jan 2008
Location:
Posts: 76
Default

Code F32:

"Code F32 is set by the BCM if a problem is detected transferring data back and forth to the PCM/ECM. If a hard code F32 is displayed upon entering diagnostics, one of the following conditions exist:

1. PCM/ECM to BCM data malfunction (CKT 526). If the BCM fails to receive data from the PCM/ECM, pin C9, over CKT 526, code F32 will be set immediately and the BCM will stop sending data to the PCM/ECM over CKT 491. When the PCM/ECM stops receiving data over CKT 491 it will set a code E47 in its memory, however, this code cannot be displayed since it would have to be sent over CKT 526 to the BCM. The loss of data to the BCM will result in a faulty instantaneous fuel economy
reading of 0 mpg at all times.

2. BCM to PCM/ECM data malfunction (CKT 491). If the PCM/ECM, pin C11, fails to receive data from the BCM over CKT 491, code E47 will be set immediately by the PCM/ECM, however, data will continue to be sent to the BCM over CKT 526. Since the BCM continues to receive data, code F32 is not set immediately and instantaneous fuel economy reading will remain accurate. Upon entering diagnostics, the BCM will attempt to request diagnostic data from the PCM/ECM but cannot due to the malfunction in CKT 491. If diagnostic data is not received shortly after diagnostics is entered, the BCM will set F32 and will be unable to display the E47 stored in PCM/ECM memory.

3. PCM/ECM CALPAK malfunction. If the PCM/ECM fails to receive data from the PCM/ECM CALPAK, the PCM/ECM will stop sending data over CKT 526 and code F32 will be set immediately. If the hard code F32 is displayed, first check to see if the PCM/ECM can illuminate its service telltales during crank. If not, the PCM/ECM is not operating properly and should be diagnosed using the Self-Diagnostic System check. If the telltales work properly, observe the instantaneous fuel economy while the vehicle is moving. A malfunction in CKT 526 will result in constant reading of 0 mpg. If the reading varies normally, the cause of the code F32 is a malfunction in CKT 491. If no circuit problem can be found, one of the two modules is unable to process the data and should be replaced."
__________________
1990 Cadillac Sedan Deville. 4.5L V8 FI. 218,000 miles

Last edited by Texan4Life; 03-03-2010 at 11:23 PM.
Reply With Quote
  #4  
Old 03-03-2010, 11:27 PM
Member
 
Join Date: Jan 2008
Location:
Posts: 76
Default

F32 diagnostic flow chart: http://i48.tinypic.com/2rxbh2h.gif

"If this code IS NOT displayed during the second pass of diagnostic codes, it is an intermittent condition and cannot be diagnosed using this procedure. For an intermittent code, refer to NOTE ON INTERMITTENTS."
__________________
1990 Cadillac Sedan Deville. 4.5L V8 FI. 218,000 miles
Reply With Quote
  #5  
Old 03-03-2010, 11:28 PM
Member
 
Join Date: Jan 2008
Location:
Posts: 76
Default

NOTE ON INTERMITTENTS :

The following conditions will result in Intermittent BCM-ECM data codes F32 and/or E47.

1. Momentary open or short in CKT 526 restilts in both F32 and E47.
2. Momentary open or short in CKT 491 results in E47 only.
3. Momentary loss of ignition (CKT 50), battery (CKT 840) or ground (CKT 751-A) to BCM results in E47 and intermittent display panel operation.
4. Momentary loss of ignition (CKT 439) to PCM/ECM in F32, and intermittent engine.
5. Momentary loss of battery (CKT 480) or ground (CKT 450) to PCM/ECM results in F32, E52 and intermittent engine operation.
6. Momentary BCM PROM problem results in E47, F51, and intermittent display of "151" on CCP.
__________________
1990 Cadillac Sedan Deville. 4.5L V8 FI. 218,000 miles
Reply With Quote
  #6  
Old 03-04-2010, 08:56 PM
slowroll's Avatar
Tech Certified Members
 
Join Date: Oct 2007
Location: Mid Atlantic
Posts: 2,505
Default

You stated concern started after bypassing PASS KEY and BCM prom change, so that is where to look first.
__________________
It will be OK
Reply With Quote
  #7  
Old 03-05-2010, 10:26 AM
stomper's Avatar
Tech Certified Members
 
Join Date: Jun 2007
Posts: 2,704
Default

hey slowroll, good to see you back ...
__________________
"If you're going through hell, keep going"
~ Winston Churchill


Reply With Quote
  #8  
Old 03-10-2010, 12:10 PM
Junior Member
 
Join Date: Mar 2010
Posts: 2
Default

got the problem fixed. put the factory burn back in the prom chip, built a pass key bypass module, and it works great. Thanks for the help everyone.
Reply With Quote
Old 03-10-2010, 12:10 PM
 
 
 
Reply



Tags
1990, bcm, body, cadillac, checking, codes, comunication, control, data, deville, ecm, losse, module, sedan, seville


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory
Our Sponsors
All times are GMT -5. The time now is 05:09 AM.

Internet Brands, Inc.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.