DIAGNOSIS
TSB Revision
CONTROLLER AREA NETWORK (CAN)
54C-145
.
FUNCTION
If the scan tool MB991958 cannot communicate with
the A/C-ECU <vehicles with A/C> or heater control
unit <vehicles without A/C>, this diagnosis result will
be set.
.
TROUBLE JUDGMENT CONDITIONS
If a communication flag is not set for the A/C-ECU
<vehicles with A/C> or heater control unit <vehicles
without A/C>, the ETACS-ECU determines that there
is a failure.
.
TROUBLESHOOTING HINTS
• Malfunction of the connector [joint connector
(CAN1), A/C-ECU <vehicles with A/C> or heater
control unit <vehicles without A/C> connector
improperly connected]
• Malfunction of the wiring harness [open circuit
between the A/C-ECU <vehicles with A/C> or
heater control unit <vehicles without A/C> con-
nector and the joint connector (CAN1), power
supply circuit to the A/C-ECU <vehicles with
A/C> or heater control unit <vehicles without
A/C>]
• Malfunction of the A/C-ECU <vehicles with A/C>
or heater control unit <vehicles without A/C>
DIAGNOSIS
Required Special Tools:
• MB991223: Harness Set
• MB992006: Extra Fine Probe
STEP 1. Check joint connector (CAN1) C-105 and A/C-ECU
connector C-22 <vehicles with A/C> or heater control unit
connector C-53 <vehicles without A/C> for loose, corroded
or damaged terminals, or terminals pushed back in the
connector.
CAUTION
The strand end of the twisted wire should be within 10 cm
(4 inches) from the connector. For details refer to
P.54C-7
.
Q: Are joint connector (CAN1) C-105 and A/C-ECU
connector C-22 <vehicles with A/C> or heater control
unit connector C-53 <vehicles without A/C> in good
condition?
YES : Go to Step 2.
NO : Repair the damaged parts.
AC708951CE
Connector: C-22
C-22 (B)
AC708950
Connector: C-105
BL