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Home >> Mazda >> 2017 >> CX-5 Grand Select, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 145 (On-Board Diagnostic - Engine Control (2 Of 5)) >> DTC P0112; Pcm At Sensor No. 1 Circuit Low Input >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED
  • Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?
Yes Go to the next step.
No Record the FREEZE FRAME DATA (Mode 2)/snapshot data 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 MAF SENSOR/IAT SENSOR NO. 1 CONNECTOR CONDITION
  • Switch the ignition off.
  • Disconnect the MAF sensor/IAT sensor No. 1 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 INSPECT IAT SENSOR NO. 1 Yes Replace the MAF sensor/IAT sensor No. 1, then go to Step 8.
(See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO. 1 REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
No Go to the next step.
5 INSPECT IAT SENSOR NO. 1 SIGNAL CIRCUIT FOR SHORT TO GROUND
  • Verify that the MAF sensor/IAT sensor No. 1 connector is disconnected.
  • Inspect for continuity between MAF sensor/IAT sensor No. 1 terminal A (wiring harness-side) and body ground.
  • Is there continuity?
Yes If the short to ground circuit could be detected in the wiring harness:
  • Refer to the wiring diagram and verify whether or not there is a common connector between MAF sensor/IAT sensor No. 1 terminal A and PCM terminal 2U.

    If there is a common connector:

    • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
      • Repair or replace the malfunctioning part.

    If there is no common connector:

    • Repair or replace the wiring harness which has a short to ground.

    If the short to ground circuit could not be detected in the wiring harness:

  • Replace the PCM (short to ground in the PCM internal circuit). (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)

Go to Step 8.
No Go to the next step.
6 INSPECT PCM CONNECTOR CONDITION
  • 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.
7 INSPECT IAT SENSOR NO. 1 SIGNAL CIRCUIT AND GROUND CIRCUIT FOR SHORT TO EACH OTHER
  • Verify that the MAF sensor/IAT sensor No. 1 and PCM connectors are disconnected.
  • Inspect for continuity between MAF sensor/IAT sensor No. 1 terminals A and B (wiring harness-side).
  • Is there continuity?
Yes Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
  • MAF sensor/IAT sensor No. 1 terminal A-PCM terminal 2U
  • MAF sensor/IAT sensor No. 1 terminal B-PCM terminal 2AY

    If there is a common connector:

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.
  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to each other.

Go to the next step.
No Go to the next step.
8 VERIFY DTC TROUBLESHOOTING COMPLETED 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 [PCM (SKYACTIV-G 2.0, SKYACTIV-G 2.5)] .)
No DTC troubleshooting completed.