ScM no comm
Thread Starter
Pro
Joined: Oct 2004
Posts: 667
Likes: 10
From: New York
ScM no comm
Hi, Please I need some help. I have 2000 auto vert stock motor with cat back borla.with about 80,000 miles. This summer I had to replace the Oil sending unit. I removed the air intake and manifold. Replaced the sensor.put everything back. About the time I hit 25 to 30 miles I got a Check engine light, P0137. Researched it and found out it was the 2nd bank 02 sensor. Today I replaced it with a Bosch 02 sensor. Disconnected the batterie to clear all the codes. All is good. "I Think" when I decided to do a manual diagnostic. I notice something new. A6 SCM. No comm. what is this? and what could be causing it. As stated I have stock motor with black wing and Borla exhaust. Can someone please help. No codes are present.
Thank you all in advance.
Thank you all in advance.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
WHY,,,
,,,,, Are you disconnecting the battery to clear the DTCs???????
No COMMS means that the other modules serial data buss is not communicating with the seat. Specifically, the BCM
There could be several reasons why the code came up but disconnecting the battery is one of them. Clear your codes using the DIC and see what you get.
Read the directions posted below and enjoy:
READING YOUR Engine Diagnostic Codes (DTCs)
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open etc…)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.
Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes)
If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, C or ;H. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present;
press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET
To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
Here is very good site of DTC definitions:
http://www.gearchatter.com
Make sure to include the H or C suffix!!
,,,,, Are you disconnecting the battery to clear the DTCs???????No COMMS means that the other modules serial data buss is not communicating with the seat. Specifically, the BCM
There could be several reasons why the code came up but disconnecting the battery is one of them. Clear your codes using the DIC and see what you get.
Read the directions posted below and enjoy:
READING YOUR Engine Diagnostic Codes (DTCs)
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open etc…)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.
Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes)
If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, C or ;H. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present;
press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET
To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
Here is very good site of DTC definitions:
http://www.gearchatter.com
Make sure to include the H or C suffix!!
Thread Starter
Pro
Joined: Oct 2004
Posts: 667
Likes: 10
From: New York
I have seen this on 2 cars. If the seat has ever been out of the car and the tech failed to properly re-secure the wiring hold downs, the wiring to the seat controller can easily be cut/damaged when the seat is operated. Difficult to see without either a mirror or removing the seat and inspecting because of the limited clearance between the floor and seat but youshould be able to see damage if it has been done with a mechanics mirror and flash light.
Suggest you do as Bill C suggested in pulling up ALL your codes and posting them here with the H or C or HC that follow each 5 character code.
Suggest you do as Bill C suggested in pulling up ALL your codes and posting them here with the H or C or HC that follow each 5 character code.
Racer
Joined: Feb 2003
Posts: 418
Likes: 28
From: Evansville IN
See that broke wire? It started out intermittent and then when it broke completely off I got the same error message your're getting.
BTW, that's under the seat. I had to take the seat control module out to see it and still didn't until the second look out in the sun.
HTH
STeve
BTW, that's under the seat. I had to take the seat control module out to see it and still didn't until the second look out in the sun.
HTH
STeve
Thread Starter
Pro
Joined: Oct 2004
Posts: 667
Likes: 10
From: New York
See that broke wire? It started out intermittent and then when it broke completely off I got the same error message your're getting.
BTW, that's under the seat. I had to take the seat control module out to see it and still didn't until the second look out in the sun.
HTH
STeve
BTW, that's under the seat. I had to take the seat control module out to see it and still didn't until the second look out in the sun.
HTH
STeve
Yes thank you....yes I agree Excellent work
