DTC P1401: EGR Temperature Sensor: Procedure
- Turn ignition off. Disconnect EGR temperature sensor harness connector. See Fig 1. Turn ignition on. Measure voltage between ground and EGR temperature sensor harness connector White wire. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short between ECM and EGR temperature sensor. Retest system.
- Turn ignition off. Check continuity between engine ground and EGR temperature sensor harness connector Black wire. Also check circuit for short to voltage. See WIRING DIAGRAMS article. Repair as necessary and retest system. If ground circuit is okay, go to next step.
- Remove EGR temperature sensor. Measure resistance between EGR temperature sensor terminals, with sensor at specified temperatures. See EGR TEMPERATURE SENSOR RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace EGR temperature sensor and retest system.
- Remove EGR Volume Control Valve (EGR-VCV). See Figure. Measure resistance between EGR-VCV terminals No. 2 and 1, 2 and 3, 5 and 4, and 5 and 6. See Figure. Resistance should be 20.9-23.1 ohms at 68°F (20°C). If resistance is not as specified, replace EGR-VCV and retest system. If resistance is as specified, go to next step.
- Reconnect all harness connectors. Ensure EGR-VCV shaft moves smoothly when ignition is turned on and off. If EGR-VCV does not operate as specified, replace EGR-VCV and retest system. If EGR-VCV operates as specified, go to next step.
- No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
EGR TEMPERATURE SENSOR RESISTANCE
| Temperature - °F (°C) | K/Ohms |
|---|---|
| 32 (0) | 680-1110 |
| 122 (50) | 90-120 |
| 212 (100) | 17-24 |