Workshop Manual

11.6. Coolant Temperature Sensor Failure
Failure codes: P0112, P0113
No. Operating steps Result Follow up steps
1 Put the ignition switch to “ON”. Next step
Yes Next step 2 Pull out joint of coolant temperature sensor on
harness; use a multimeter to check if the
magnitude of voltage between 1# (+) and 2# (-)
pins of this joint is around 5V.
No 4
Yes Replace ECU 3 Use a multimeter to check if the resistance value
between 1# and 2# pins of the sensor is in
proportion to its temperature (refer to relevant part
in this service manual).
No Replace the sensor
Yes Repair or replace
harness
4 Use a multimeter to check if it is break or short
circuit between 17# and 29# pins of ECU and 2#
and 1# pins of sensor joint.
No Replace ECU
Yes Next step 5 Start the engine, while engine coolant temperature
rises, check if the voltages on two wires of the
sensor falls as water temperature of the engine
rises.
No Replace the sensor
Yes Check other part 6 Start the engine, disconnect the connector of water
temperature sensor, and then observe if cooling
fan of the engine starts up and runs at high speed.
No Replace the ECU or
the circuit