Hi, I'm having problems communicating with the transmission (TCM). I'm using a clone ELM327, controlled by an Arduino Mega. Everything works fine communicating with the ECM (engine control module). My '06 Sprinter uses KWP2000 protocol.
I disconnected the ELM K-line output which connects to the OBD2 connector pin 3 (ECM K-line) and then connected ELM output to OBD2 connector pin 11 (TCM K-line).
I know the wake-up command for the TCM is: 81 20 F1 81 15
20 is the address for the TCM.
I also know the header for the TCM: 82 20 F1
My problem is getting the ELM327 setup. Here's what I'm doing:
ATZ
AT L1
AT E1
AT SP 5
AT SI
AT H1
AT KW
AT IIA 20
AT WM 81 20 F1
AT SH 82 20 F1
ELM's response to these commands is:
> ATZ: ELM327 v1.5
>AT L1: OK
>AT E1: OK
>AT SP5: OK
>AT SI: ?
>AT H1: OK
>AT KW 0: ?
>AT IIA 20: ELM327 v1.5
>AT WM 81 20 F1 81: ?
>AT SH 82 20 F1: OK
The "?" means I'm using the wrong protocol or I have a typo. However, I'm using protocol 5 which is KWP2000, and AT KW 0 should be OK. The response from AT IIA 20 is also strange.
With this setup, the ELM sends on the K-line this wake up command: C1 33 F1 81 66
That is the wake up command for the ECU.
Has anybody communicated (using an ELM clone) with another module other than the engine? Can it be done?
Thanks