Component Inspection

Air Conditioner

B1202 Water temp sensor open (High) - Component Inspection

Component Inspection

1. Check Water temp. sensor
(1) Ignition "OFF"
(2) A/C-ECU, Water temp. sensor : Connect.
(3) Measure resistance between Signal (+) terminal of Water temp. sensor harness connector and and Sensor ground terminal of Water temp. sensor harness connector. (Component side)
A. Specification : Refer the specifications in fig.1








FIG.1) ** Specifications : Resistance value of water temp sensor as a function of temperature.
** The actual value may differ from it according to various engine condition.
(4) Is "resistance" display near the specified value?
YES
1) Go to "Check A/C-ECU" procedure.
NO
1) Substitute with a known-good Water temp. sensor and check for proper operation. If the problem is corrected, replace Water temp. sensor and then go to "Verification of Vehicle Repair" procedure.
2. Check A/C-ECU
(1) Ignition "OFF"
(2) A/C-ECU : Connect, Water temp. sensor : Disconnect.
(3) Ignition "ON"(ENGINE "OFF").
(4) Measure voltage between Signal (+) terminal of Water temp. sensor connector and and chassis ground. (Component side)
A. Specification : Approx. 5 V




(5) Is "voltage" display near the specified value?
YES
1) Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Substitute with a known-good A/C-ECU and check for proper operation. If the problem is corrected, replace A/C-ECU and then go to "Verification of Vehicle Repair" procedure.