AUTOMATIC A/C DIAGNOSIS
TSB Revision
AUTOMATIC AIR CONDITIONING
55B-11
STEP 4. Check the wiring harness between A/C-ECU
connector C-109 (terminals 17 and 19) and interior
temperature sensor connector C-122 (terminals 2 and 1).
• Check the sensor signal line and ground line for open and
short circuit.
Q: Is the wiring harness between A/C-ECU connector
C-109 (terminals 17 and 19) and interior temperature
sensor connector C-122 (terminals 2 and 1) in good
condition?
YES : Go to Step 5.
NO : Repair the wiring harness.
STEP 5. Check the interior temperature sensor.
Measure the resistance between connector terminals 1 and 2
under at least two different temperatures. The resistance val-
ues should generally match those in the graph.
NOTE: The temperature at the check should not exceed the
range in the graph.
Q: Is the interior temperature sensor in good condition?
YES : Replace the A/C-ECU. Then go to Step 6.
NO : Replace the interior temperature sensor. Then go to
Step 6.
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the check result satisfactory?
YES : The procedure is complete.
NO : Return to Step 1.
AC702920
20
15
10
5
0
-10
(14)
0
(32)
20
(68)
10
(50)
30
(86)
40
(104)
AB
RESISTANCE
TEMPERATURE ˚C (˚F)