DTC P0426 Exhaust Gas Temperature (EGT) Sensor 1 Circuit Range/Performance (4JJ3 with DPD)

Note

  • If the exhaust gas temperature is excessively high, this DTC is set. Uncontrollable combustion during DPD filter regeneration process is most likely the cause of this. The DPD filter or catalytic converter may be damaged when the exhaust gas temperature is excessively high.
  • If there is a problem with the fuel system such as fuel injector damage, this DTC is set.

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Diagnostic system check-engine controls".

2. Prioritized DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Start the engine.

4) Observe the DTC information with a scan tool. Is DTC P0427 or P1093 set at the same time?

Yes

Go to the applicable DTC diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC P0427 Exhaust Gas Temperature (EGT) Sensor 1 Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC P1093 Fuel Rail Pressure (FRP) Too Low".

No

=>Go to Exhaust gas temperature sensor 1 (front of DPD filter) inspection.

3. Exhaust gas temperature sensor 1 (front of DPD filter) inspection

1) Test Exhaust gas temperature sensor 1 (front of DPD filter) at various temperatures, and evaluate the possibility of sensor malfunction. Is the result normal?

Yes

=>Go to DPD inspection.

No

Replace Exhaust gas temperature sensor 1 (front of DPD filter) as necessary.

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) exhaust gas temperature sensor 1 (Front of DPD filter) removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) exhaust gas temperature sensor 1 (Front of DPD filter) installation".

=>Go to Repair verification.

4. DPD inspection

1) Remove the DPD.

Refer to "1.Engine 1G.Exhaust(4JJ3 with DPD) DPD removal".

2) Inspect the DPD for damage, cracking, or melting. Is the result normal?

Yes

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 with DPD) intermittent conditions of engine".

No

Replace the DPD.

Note

  • If the DPD is replaced, reset the DPD status in the ECM.

Refer to "1.Engine 1G.Exhaust(4JJ3 with DPD) DPD removal".

Refer to "1.Engine 1G.Exhaust(4JJ3 with DPD) DPD installation".

=>Go to Repair verification.

5. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Start the engine.

4) Operate the vehicle under the conditions for running the DTC.

5) Observe the DTC information with a scan tool.

Copyright Mazda Motor Corporation. All rights reserved.