Test Procedure
- Turn ignition off. Connect Hi-Scan Pro/Kia Data Pro Scan tool or equivalent to OBD-II Data Link Connector. See Figure
. Start engine. Allow engine to idle until reaches normal operating temperature. Monitor ECT sensor voltage signal. See ENGINE COOLANT TEMPERATURE SENSOR OUTPUT VOLTAGE SPECIFICATION
table. If voltages are as specified. Problem is intermittent, check ECT sensor and ECM for proper harness connections and go to step 8
. If any voltage is not as specified, go to next step.ENGINE COOLANT TEMPERATURE SENSOR OUTPUT VOLTAGE SPECIFICATION
ECT Sensor Output - Voltage ECT Sensor Temperature - °F (°C) 3.4-3.6 68 (20) 1.1-1.3 176 (80) - Turn ignition off. Thoroughly check ECT sensor. Also check for loose, bent or corroded ECT sensor orECM connectors terminals. If sensor and connectors terminals are okay, go to next step. If sensor and connectors terminals are faulty, repair or replace as necessary and go to step 8 .
- Remove thermostat and check if thermostat is stuck. If thermostat is stuck, replace thermostat and go to step 8 . If thermostat is okay, go to next step.
- Disconnect ECT sensor 3-pin harness connector. See Fig 1 . Turn ignition on. Measure voltage between ground and ECT sensor connector terminal No. 1 (Blue/Yellow wire). Voltage should be approximately 5 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair open or short circuit as necessary and go to step 8 .
- Turn ignition off. Disconnect ECM 81-pin harness connector. See Figure . Measure resistance between ECT sensor connector terminal No. 1 (Blue/Yellow wire) and ECM connector terminal No. 39. Also measure resistance between ECT sensor connector terminal No. 3 (Violet/White wire) and ECM connector terminal No. 35. Both resistances should be below one ohm. If resistances are as specified, go to next step. If any resistance is not as specified, repair open or short circuit as necessary and go to step 8 .
- With ECT sensor and ECM harness connectors disconnected. Turn ignition on. Measure voltage between ground and ECT connector terminal No. 1 (Blue/Yellow wire). Voltage hold be below 0.5 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair short circuit as necessary and go to step 8 .
- Turn ignition off. With ECT sensor and ECM harness connectors disconnected. Measure resistance between ground and ECT sensor connector terminal No. 1 (Blue/Yellow wire). Also measure resistance between ECT sensor connector terminal No. 1 (Blue/Yellow wire) and No. 3 (Violet/White wire). Both resistances should be infinite. If resistances are as specified, temporarily install a known-good ECT sensor and check for proper operation. If problem is corrected, replace ECT sensor and go to next step. If any resistance is not as specified, repair short circuit as necessary and go to next step.
- After repair, return vehicle to original condition. Clear codes using Hi-Scan Pro/Kia Data Pro Scan tool or equivalent. Verify repairs by driving vehicle and monitoring for pending codes. If DTC is set during test drive, follow appropriate DTC test procedure.