MANUAL A/C DIAGNOSIS
TSB Revision
HEATER, AIR CONDITIONING AND VENTILATION
55A-51
STEP 2. Using scan tool MB991958 read the Occupant
classification-ECU diagnostic trouble code.
Check whether an Occupant classification-ECU DTCs are set
or not.
(1) Turn the ignition switch to the "ON" position.
(2) Check for Occupant classification-ECU DTCs.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Go to Step 3.
NO : Diagnose the Occupant classification-ECU (Refer to
GROUP 52B, Diagnostic Trouble Code
P.52B-344
).
STEP 3. Using scan tool MB991958, check for any
diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked
systems below, is set.
• ETACS-ECU
DTC indicating a time-out error related to the Occupant
classification-ECU system
(1) Turn the ignition switch to the "ON" position.
(2) Check for a DTC related to the relevant system.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : A poor connection, open circuit or other intermittent
malfunction is present in the lines between the
SRS-ECU and the A/C-ECU (Refer to GROUP 00E,
Harness Connector Inspection
P.00E-2
.)
NO : Replace the Occupant classification-ECU. On
completion, check that the DTC is not reset.
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Check if the DTC is set.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : A poor connection, open circuit or other intermittent
malfunction is present in the lines between the
SRS-ECU and the A/C-ECU (Refer to GROUP 00E,
Harness Connector Inspection
P.00E-2
.)
NO : Replace the A/C-ECU. On completion, check that the
DTC is not reset.