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Home >> Mazda >> 2017 >> 5 GT, Standard Trans >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic - Engine Control (1 Of 3) >> DTC P0118-00: ECT Sensor Circuit High Input >> Diagnostic Procedure
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Diagnostic Procedure

DTC P0118:00 DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
  • Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (engine cooling system related) been recorded?
 Yes Go to the next step.
No Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
 Yes Perform repair or diagnosis according to the available repair information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
3 INSPECT ECT SENSOR CONNECTOR CONDITION
  • Switch the ignition to off.
  • Disconnect the ECT sensor connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 8.
No Go to the next step.
4 CLASSIFY ECT SENSOR MALFUNCTION OR WIRING HARNESS MALFUNCTION
  • Verify that the ECT sensor connector is disconnected.
  • Access the ECT PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST .)
  • Connect a jumper wire between ECT sensor terminals A and B (wiring harness-side).
  • Verify the ECT PID value.
  • Is the voltage 4.6 V or below?
 Yes Replace the ECT sensor, then go to Step 8.
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)
No Go to the next step.
5 INSPECT PCM CONNECTOR CONDITION
  • Switch the ignition to off.
  • Disconnect the PCM connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 8.
No Go to the next step.
6 INSPECT ECT SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
  • Verify that the ECT sensor and PCM connectors are disconnected.
  • Switch the ignition to ON (engine off).
  • Measure the voltage at the ECT sensor terminal A (wiring harness-side).
  • Is there any voltage?
 Yes Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
No Go to the next step.
7 INSPECT ECT SENSOR CIRCUIT FOR OPEN CIRCUIT
  • Verify that the ECT sensor and PCM connectors are disconnected.
  • Switch the ignition to off.
  • Inspect for continuity between the following terminals (wiring harness-side):
    • ECT sensor terminal A-PCM terminal 2AH
      • ECT sensor terminal B-PCM terminal 2AV
  • Is there continuity?
 Yes Go to the next step.
No Repair or replace the wiring harness for a possible open circuit, then go to the next step.
8 VERIFY DTC TROUBLESHOOTING COMPLETED
  • Make sure to reconnect all disconnected connectors.
  • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE .)
  • Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST .)
  • Is the same DTC present?
 Yes Repeat the inspection from Step 1.

Go to the next step.
No Go to the next step.
9 VERIFY AFTER REPAIR PROCEDURE
 Yes Go to the applicable DTC inspection.
(See DTC TABLE .)
No DTC troubleshooting completed.
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