DTC P0400: EGR Function Or Flow Malfunction
NOTE:
After each repair, clear DTCs. See CLEARING CODES/PCM RESET PROCEDURE
under SELF-DIAGNOSTIC SYSTEM. Turn ignition off and then on. Read DTCs to verify repair is complete. For DLC and PCM connector terminal identification, see CONNECTOR IDENTIFICATION
. For wiring diagrams, see WIRING DIAGRAMS
.
- Using scan tool, read DTCs. If DTC P0400 is present, turn ignition off. Ensure EGR valve and temperature sensor harness and connectors are not damaged and connections are okay. Repair as necessary. If harness and connectors are okay, go to next step.
- Ensure EGR temperature sensor is installed correctly. Repair as necessary. Disconnect EGR temperature sensor harness connector. Using DVOM, check resistance across temperature sensor terminals. See EGR SENSOR RESISTANCE SPECIFICATIONS table. If resistance is within specification, go to next step. If resistance is not within specification, replace temperature sensor.
- Check for continuity of Red/Brown wire between temperature sensor connector terminal No. 1 and PCM Red connector terminal No. 3, and of Black/Green wire between temperature sensor connector terminal No. 2 and PCM Red connector terminal No. 30. Repair wiring as necessary. If wiring is okay, go to next step.
- Check for gas leak or blockage and repair as necessary. Check for any IAT sensor, TP sensor or MAF sensor DTCs. If component DTCs are present, repair as necessary. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION . If component DTCs are not present, clear DTCs. Turn ignition off and then on. Read DTCs. If DTC P0400 is not present, repair is complete. If DTC P0400 is present, replace PCM.
EGR SENSOR RESISTANCE SPECIFICATIONS
| Temperature F° (C°) | (1) k/ohms | ||
|---|---|---|---|
| 122 (50) | 800,000 | ||
| 212 (100) | 100,000 | ||
| 302 (150) | 50,000 | ||
| 392 (200) | 9000 | ||
| 482 (250) | 3000 | ||
| 572 (300) | 1000 | ||
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