1990 Deville BCM/ECM communications problems!
#1
03-01-2010, 03:09 PM
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.
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.
#2
03-01-2010, 03:37 PM
pretty close to 100% of electronics issues are related to e-ghosts.
have you read our FAQ thread on e-ghosts?
have you read our FAQ thread on e-ghosts?
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.
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.
#3
03-03-2010, 11:20 PM
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."
"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."
Last edited by Texan4Life; 03-03-2010 at 11:23 PM.
#4
03-03-2010, 11:27 PM
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."
"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."
#5
03-03-2010, 11:28 PM
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.
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.
#8
03-10-2010, 12:10 PM
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.
#9
08-13-2021, 04:53 PM
Before you swap BCM or ECM
Just a helpful hint, a maybe before replacing bcm and ecm. Check your battery and battery connectors. My battery would make just a good enough connection to start and run but bad enough to throw these related codes. Fix ended up being a new terminal bolts. Could have saved a world of confusion and parts.
1991 Cadillac Deville
1991 Cadillac Deville
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