DTC P1408/17816 - EGR Temperature Sensor Signal Too High
NOTE:
DTC is set when EGR temperature sensor signal is less than 41°F (5°C) for more than 32 seconds with idle switch open, coolant temperature more than 162°F (72°C), throttle angle less than 42.5 degrees, vehicle speed 44-66 MPH, EGR valve duty cycle more than 50 percent, engine speed 1500-3300 RPM and engine load 16-60 percent.
- Inspect EGR temperature sensor for looseness and/or corrosion. EGR temperature sensor is located on intake manifold under throttle body. Repair connector as necessary. If connector was not repaired, go to next step. If connector was repaired, erase DTC memory and test drive vehicle.
- Disconnect EGR temperature sensor electrical connector. Turn ignition on. Using a DVOM, measure voltage between EGR temperature sensor harness connector terminals. Voltage should be approximately 5 volts. If voltage is to specification, go to step 4). If voltage is not to specification, go to next step.
- Repair open circuit between EGR temperature sensor harness connector terminal No. 1 and PCM connector "A" terminal No. 23, and/or between EGR temperature sensor harness connector terminal No. 2 and engine ground. Erase DTC memory and test drive vehicle.
- Turn ignition off. Remove EGR temperature sensor from engine. Using a DVOM on 200 k/ohm scale, connect leads to EGR temperature sensor terminals. Immerse EGR temperature sensor in hot water 176-212°F (80-100°C). Observe DVOM reading. Resistance should change. If resistance changes, go to next step. If resistance does not change, replace EGR temperature sensor. Erase DTC memory and test drive vehicle.
- EGR temperature sensor is okay. Replace faulty PCM. Code new PCM and test drive vehicle. See PCM CODING in this article.