Test Dr-13A - Testing EGR Temperature Sensor (CALIFORNIA) (Code 43)

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For appropriate wiring diagram, see WIRING DIAGRAMS at end of article.

Using DRB-II, erase faults. Start engine, and let it idle for more than one minute. Read faults. If Code 43 is displayed again, go to next step. If Code 43 is not displayed again, wiggle EGR temperature sensor wiring harness while monitoring DRB-II display. If Code 43 is not set when wiring harness is wiggled, perform TEST DR-14A. If Code 43 is set when wiring harness is wiggled, repair wiring harness causing Code 43 to set. Perform TEST VER-2.
Read EGR temperature sensor value. Disconnect vacuum hose from EGR valve. Using an auxiliary vacuum pump, apply 5 in. Hg to EGR valve. If engine RPM does not drop, replace EGR valve. Perform TEST VER-2. If engine RPM drops and EGR temperature sensor value increases, go to step 8).
If engine RPM drops and EGR temperature sensor value does not increase, disconnect EGR temperature sensor connector. If EGR temperature sensor value is 10°F (-12°C) when EGR temperature sensor connector is disconnected, go to step 5).
If EGR temperature value is 606°F (319°C) when EGR temperature sensor connector is disconnected, repair Dark Blue/Yellow wire between EGR temperature sensor connector terminal No. 2 and ECU 24-pin connector terminal No. 15 for a short to ground. Perform TEST VER-2. If EGR temperature sensor value is not 606°F (319°C) when EGR temperature sensor connector is disconnected, replace EGR temperature sensor. Perform TEST VER-2.
Connect jumper wire across EGR temperature sensor connector terminals. If EGR temperature sensor value is 606°F (319°C), replace EGR temperature sensor. Perform TEST VER-2. If EGR temperature value is not 606°F (319°C), turn ignition switch to OFF position. Measure resistance between EGR temperature sensor Dark Green/Black wire and ground.
If resistance is more than 10 ohms, repair Dark Green/Black wire between EGR temperature sensor and splice. Perform TEST VER-2. If resistance is less than 10 ohms, disconnect ECU 24-pin connector. Measure resistance of Dark Blue/Yellow wire between ECU 24-pin connector terminal No. 15 and EGR temperature sensor connector terminal No. 2.
If resistance is less than 10 ohms, replace ECU. Perform TEST VER-2. If resistance is more than 10 ohms, repair open Dark Blue/Yellow wire. Perform TEST VER-2.
Turn engine off. Turn ignition switch to ON position. Using DRB-II, actuate EGR solenoid. If EGR solenoid clicks, repair leak or restriction in EGR vacuum hose or solenoid. Perform TEST VER-2.
If EGR solenoid does not click, stop actuator test. Disconnect EGR solenoid connector. Measure voltage between EGR solenoid connector terminal No. 1 (Yellow/White wire) and ground. If voltage is less than 10 volts, repair open Yellow/White wire between fuel injection control relay and EGR solenoid. Perform TEST VER-2.
If voltage is more than 10 volts, measure resistance across EGR solenoid terminals. If resistance is not 30-50 ohms, replace EGR solenoid. Perform TEST VER-2. If resistance is 30-50 ohms, turn ignition switch to OFF position.
Disconnect ECU 18-pin connector. Measure resistance between ECU 18-pin connector terminal No. 53 (Brown/White wire) and ground. If resistance is less than 10 ohms, repair Brown/White wire for a short to ground. Perform TEST VER-2. If resistance is more than 10 ohms, measure resistance of Brown/White wire between ECU 18-pin connector terminal No. 53 and EGR solenoid connector terminal No. 2.
If resistance is less than 10 ohms, replace ECU. Perform TEST VER-2. If resistance is more than 10 ohms, repair open Brown/White wire between ECU connector and EGR solenoid connector. Perform TEST VER-2.