Dtc U0073: Control Module Communication Bus Off; Dtc U0100: Lost Communication With Ecm; Inspection Of Tcm And Its Circuits - Suzuki SX4 Service Manual

5A-78 Automatic Transmission/Transaxle:

DTC U0073: Control Module Communication Bus Off

Refer to "Troubleshooting for CAN-DTC in Section 1A".
DTC U0100: Lost Communication with ECM / PCM "A"
Refer to "Troubleshooting for CAN-DTC in Section 1A".

Inspection of TCM and Its Circuits

TCM and its circuits can be checked at TCM wiring connectors by measuring voltage, pulse signal and resistance.
CAUTION
!
TCM cannot be checked by itself, it is strictly prohibited to connect voltmeter or ohmmeter to TCM with
connector disconnected from it.
1) Remove TCM (1) from vehicle referring to "Transmission Control Module (TCM) Removal and Installation".
2) Connect TCM connectors (2) to TCM.
3) Check voltage and/or pulse signal at each terminal of connectors connected using voltmeter (3) and oscilloscope
(4).
NOTE
• As each terminal voltage is affected by battery voltage, confirm that it is 11 V or more when ignition
switch is ON.
• Voltage with asterisk(*) cannot be measured by voltmeter because it is pulse signal. Check it with
oscilloscope if necessary.
Terminal arrangement of TCM coupler (Viewed from harness side)
1
3
C06
6 5
4 3 2 1
16 15 14 13 12 11 10 9 8 7
20 19 18 17
24 23 22 21
2
4
I4RS0A510021-02
C07
1
6 5 4 3 2
17 16 15 14 13 12 11 10 9 8 7
21 20 19 18
26 25 24 23 22
I6RW0B510018-01
S7RW0A5104044
S7RW0A5104045
S7RW0A5104046