2007 Acura Tsx No communication with ecm/tcm
This vehicle had a ecm/tcm replaced by another shop due to flood damage, it started and drive, now that the vehicle needs smog it won't communicate. The only odd thing that i see is that when I check the fuses, there is an interruption by voltage, meaning it is hard to read the voltage from the lower fuses by the kick panel. And there was corrosion on two connections that I cleaned by adding electric cleaner and cleaning the terminals. It still will not communicate. Any thoughts or advice wokld be much appreciated.
Can you comm with other modules ??
Looking at a network diagram, I see that this is CAN network vehicle and that all the modules, and the DLC, are linked together through C554. Since this was a flood car, I would find C554 and look for corrosion inside of it.
Can you comm with all other modules ??? On can network
I'd put a meter on pin 6 and 14 and make sure you have a signal at each pin. Better with a breakout box so you can see what your scanner sees. I had a Mazda that wouldn't communicate with any DAD, and it was due to one damaged pin at the DLC.
Can you comm with other modules . Did you do a full scan on other modules ??
I said meter because people get so worked up over whether a scope would be necessary to view any activity on either pin. I personally used my uScope that I purchased from AESWave. aeswave.com/uScope-Basic-K… On one pin I saw normal activity, and just a flat line on the other. A decent DVOM with min/max would suffice for this test, IMO.
I could only communicate with one module, and I don't remember what it was. It was able to communicate on one leg of the CAN bus. There were no "U" codes in the module. My problem wasn't with the modules communicating with each other, my problem was that the scanner wouldn't communicate with most of the modules on the CAN bus.
Try a different scan tool . Did you scope it ??
Flat line high or low . Looks like network problem . You need more than the u scope . If you can not afford pico use snap on or hanteck
Thank you all for all the great responces, I did check for activity with a snap on 2 channel lab scope. Yes I can communicate with other modules. Great advice on checking the connection, I would have to find it on monday on all data. Thanjs to all and I will keep you up to date
Does anyone know how much voltage is supposed to be on the K-line, also I could not find it on the ecm/tcm connections. But I did on dlc. Does someone have any advice on that? Thanks
Do not worry about voltage it should be at lest 9 volts on k line system . But if you can comm to other modules you should be good . No wave form at ecm I would suspect break in harness
I was trying to attach pictures, but it would not let me, I can communicate with other modules except ecm/tcm. I checked the can low and can high with labscope it seems to be ok. There are other codes from modules stating 83-1 and code 86-1. Ecm/pcm relation failure 2. Can relation failure. I still need to find out where to find that connection c554. Thanks to all I will check on monday and you…
Do you have can system or k line system or both
According to all data I saw can and k-line
Were is the gateway ??? Instrument cluster ???
I am out of ideas, C554 is towards the top and cannot acces, also water damage was only on lower part of vehicle and only got the cables wet around the feet area. I also already checked for a can low and high with snap on scope on the computer side and on the instrument side and they both have good paterns and mirror each other. Let me know what you guys think and thank you once again for your…
What other modules are on the can network ??
The instrument cluster and pcm/ecm
Did the other shop replace with new ecm or used ?? You call ecm or cluster . I would try used ecm to see if you can comm . Not un commune for cluster to go bad .
Daniel, can you see the VSA (ABS) or TPMS controllers? If not, you might try to disconnect them. Just throwing a WAG.
The shop replaced with used ecm and then reprogrammed. Yes danny I can communicate with abs and tpms controls.
The shop had to been able to connect to the ECM to program it. It communicates in enhanced? It doesn't communicate in Generic for the smog inspection?
It comm in enhanced ???? Not in generic . Its a software iss in ecm
That is a great question, I will ask the shop owner tomorrow how they programed it if there is no communication, unless some of the corrosion got worse with time.
Daniel. Few thigs to consider. 1- The ECM/TCM has a terminating resistance of 60 Ω ohms. 2- The Cluster has terminating resistance of 60Ω ohms. 3- If the resistance of the cluster or the ECM/PCM is blown yuo will have only 60Ω at the can pins at the obd2 connector, must be 120Ω with all modules connected. 4. Codes 83 and 86 are not clearing with scanner, has to be manual erase. Code 83 is…