CCM code 41....Help
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,524
Likes: 1
From: King Ranch, 2015 GTR 2008 Z06 Viper Texas
CCM code 41....Help
after buttoning everything up after installing a clutch master and slave cylinder my 91 started acting up. the check engine light came on and the sys would flash. My manual led me to swap out the mem cals- (no change), SWAP OUT COMPUTERS (NO CHANGE), then I retrieved the CCM code 41. What would be the most likely cause of a loss of ECM serial data communications?
This am I am going to check the CCM connectors and anything else suggested.
Thanks in advance!
This am I am going to check the CCM connectors and anything else suggested.
Thanks in advance!
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Code 41 - faulty or incorrect mem-cal : Check mem-cal lock tabs are secure.
Tes per helms:
1. ign off, clear codes; start engnine and run 1 minute or until code 41 sets
2. if code 41 sets: ign off; disconnect ecm connections ; probe terminals D3, D1, D10, A12 w/test lite connected to 12v
3. Light On: faulty connections or mem-cal or incorrect mem-cal installed
Light Off: Repair open ground CKT 450
Tes per helms:
1. ign off, clear codes; start engnine and run 1 minute or until code 41 sets
2. if code 41 sets: ign off; disconnect ecm connections ; probe terminals D3, D1, D10, A12 w/test lite connected to 12v
3. Light On: faulty connections or mem-cal or incorrect mem-cal installed
Light Off: Repair open ground CKT 450
Advanced
Joined: Feb 2004
Posts: 72
Likes: 0
From: Huntsville Alabama
Originally Posted by 383LPE
Thanks, but I am looking for help with the CCM code 41 "ECM serial data circuit - loss of data".
On my 93, I solved the problem by replacing the ECM. Mine was temperature sensitive so I could confirm with an ice bag.
Problem also can be caused by open serial line. Shorted serial line has additional symptoms that you did not mention.
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
A serial line data loss can be caused by:
1) Serial line shorted to ground
2) Serial line open
3) No data being sent
Since there are supposedly two wires in parallel, it is unlikely that the line is open.
If your vehicle is like my '92, you can have four computers communicating on the serial line:
1) ECM
2) CCM
3) ASR/ABS computer
4) C68 Electronic climate control
Your car can run with only the ECM and CCM connected.
By disconnecting the ASR/ABS and C68 climate control connectors, you can eliminate them as being the problem -- if the problem still exists, this will leave only the ECM and CCM or the serial link itself as the problem. My problem was the ECM.
Tom Piper
1) Serial line shorted to ground
2) Serial line open
3) No data being sent
Since there are supposedly two wires in parallel, it is unlikely that the line is open.
If your vehicle is like my '92, you can have four computers communicating on the serial line:
1) ECM
2) CCM
3) ASR/ABS computer
4) C68 Electronic climate control
Your car can run with only the ECM and CCM connected.
By disconnecting the ASR/ABS and C68 climate control connectors, you can eliminate them as being the problem -- if the problem still exists, this will leave only the ECM and CCM or the serial link itself as the problem. My problem was the ECM.
Tom Piper
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,524
Likes: 1
From: King Ranch, 2015 GTR 2008 Z06 Viper Texas
thanks tom, great responce. maybe you can help me trouble shoot this out.
This started after the clutch master install, and I am wondering if I disconected something with my big hands under the dash.
when I read the ccm code and got the 41 (ecm serial loss), the ccm gave me an ERR on module 4 and 7. I think these represent the abs and or the ac.
I secured another CCM and installed it, no change. I tested the circuits on the CCM plugs and things checked allright...I guess. I'll need to do some more, but this is very frustrating.
any tips on how to better check the abs or ac?
This started after the clutch master install, and I am wondering if I disconected something with my big hands under the dash.
when I read the ccm code and got the 41 (ecm serial loss), the ccm gave me an ERR on module 4 and 7. I think these represent the abs and or the ac.
I secured another CCM and installed it, no change. I tested the circuits on the CCM plugs and things checked allright...I guess. I'll need to do some more, but this is very frustrating.
any tips on how to better check the abs or ac?
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Advanced
Joined: Feb 2004
Posts: 72
Likes: 0
From: Huntsville Alabama
If you were rough behind the dash, there is Splice S222 that ties all the serial lines together that maybe damaged. On the 92/93 at least, it is located in the Intrument Panel Harness near the Cruise Control Module. also the service manual provides a diagnostic chart to follow for Code 41 that checks continuity, opens, and shorts.
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,524
Likes: 1
From: King Ranch, 2015 GTR 2008 Z06 Viper Texas
Thanks. That splice 222 is a nest!
I have worked through the diag chart, and am doing so again. I am trying to trace down a possible open to B+ on ct 800.
Ideas appreciated.
I have worked through the diag chart, and am doing so again. I am trying to trace down a possible open to B+ on ct 800.
Ideas appreciated.
Intermediate
Joined: Aug 2013
Posts: 36
Likes: 0
A serial line data loss can be caused by:
1) Serial line shorted to ground
2) Serial line open
3) No data being sent
Since there are supposedly two wires in parallel, it is unlikely that the line is open.
If your vehicle is like my '92, you can have four computers communicating on the serial line:
1) ECM
2) CCM
3) ASR/ABS computer
4) C68 Electronic climate control
Your car can run with only the ECM and CCM connected.
By disconnecting the ASR/ABS and C68 climate control connectors, you can eliminate them as being the problem -- if the problem still exists, this will leave only the ECM and CCM or the serial link itself as the problem. My problem was the ECM.
Tom Piper
1) Serial line shorted to ground
2) Serial line open
3) No data being sent
Since there are supposedly two wires in parallel, it is unlikely that the line is open.
If your vehicle is like my '92, you can have four computers communicating on the serial line:
1) ECM
2) CCM
3) ASR/ABS computer
4) C68 Electronic climate control
Your car can run with only the ECM and CCM connected.
By disconnecting the ASR/ABS and C68 climate control connectors, you can eliminate them as being the problem -- if the problem still exists, this will leave only the ECM and CCM or the serial link itself as the problem. My problem was the ECM.
Tom Piper
