DIY PGMFI Diagnostics - Code 12 EGR Lift

[ECU-MAN]

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!


No part of this DIY is to be reproduced with out acknowledgment of the site and author it came from, ie me and ozhonda.com. Do not rip parts off and claim them as your own.


EGR Lift Solenoid sensor "Exhaust Gas Recirculation". The EGR Lift sensor is commonly located on the front of Intake Manifold. The ECU uses the EGR Lift sensor to measure the EGR valve opening, then adjusting the EGR solenoid duty cycle to control EGR Valve lift.








Aim:

Diagnose code 12.






Required:

Basic Testing

- Digital Multi Meter
- paper clip
- vacuum pump





Symptoms

A faulty EGR Lift sensor to trigger code 12, you will more than likely get the engine light come on. Drivability may not suffer, just a code gets stored in ECU memory.


Basic Test


- Perform a Visual inspection and make sure the EGR sensor is Connected, also ensure the vacuum line is connected. Ensure the EGR Solenoid is functioning.


EGR Sensor Pin out Picture




wire side of connector


**** Voltage Test ****


Set your multi meter to DC Volts ( 20v scale )

Step 1 ( Reference Voltage test )



Check the EGR Lift sensor for its Reference Voltage from the ECU, Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the EGR Lift sensor with the Red lead to Pin 3 of the EGR lift sensor while the sensor is disconnected.

KOEO* you must get 5v

If you get 5v proceed to step 2,


if you do not get 5v, repair open or short circuit to ECU from Pin 3 to the bellow ECU Pin ( also see continuity test below )

OBDO = n/a
OBDI = D19
OBDIIa = D4
OBDIIb = C19

If you do not get 5v from the ECU pin above, replace the ECU.



STEP 2

Check EGR Lift sensor for a good ground. Leave your Red lead from the above test on Pin 3. Back probe your Black lead into Pin 2 of the EGR Lift Sensor.

KOEO* you must get 5v

If you get 5v proceed to step 3,


if you do not get 5v, repair open or short circuit to ECU from Pin 2 of EGR Lift to the bellow ECU Pin ( also see continuity test below )

OBDO = n/a
OBDI = D22
OBDIIa = D11
OBDIIb = C18


Leave your Black lead of the multi meter as is and move the Red Lead from Pin 3 of the EGR Lift to the positive battery terminal. You should get 12v. If not, repair the wire between Pin 2 of the EGR and Pin listed above to the ECU.


STEP 3


Check the EGR Lift Signal. Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the EGR Lift with the Red lead to Pin 1 of the EGR Lift sensor while the sensor is connected.


KOEO* you should get about 1v, the EGR Valve will be fully closed.

using a vacuum pump apply vacuum to the EGR valve, as you add vacuum the voltage increases to about 4.5v and the EGR Valve opens.


as EGR Lift increases, EGR lift sensor voltage increases

If you do not get a signal on Pin 1 but just get 5v, replace the EGR assy with a known good one and retest. If you do get a signal at Pin 1, then check the signal at the ECU end.



OBDO = n/a
OBDI = D12
OBDIIa = D9
OBDIIb = ?



If you get a good signal at Pin 1 on the EGR Lift and no signal on the above ECU Pin, repair the Open circuit between the above ECU Pin and Pin 1 of the EGR Lift Sensor.



***** Its is always best to check sensor inputs at the ECU side *****



**** Continuity Test ****


Set your multi meter to continuity. This setting is mostly a picture if a sound .))) when you touch the Red and Black leads together on your meter it should beep.





STEP 1

make sure the Ignition is off and unplug the EGR Connector and the ECU Connectors for this test

Continuity test between EGR Lift Pin 1 and ECU, Connect your Red multi meter lead on the EGR Lift Pin 1, Back probe* the Black multi meter lead on the ECU Pin below that suits your car.





OBDO = n/a
OBDI = D12
OBDIIa = D9
OBDIIb = ?




your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.



STEP 2

make sure the Ignition is off and unplug the EGR Connector and the ECU Connectors for this test

Continuity test between EGR Lift Pin 2 and ECU, Connect your Red multi meter lead on the EGR Lift Pin 2, Back probe* the Black multi meter lead on the ECU Pin below that suits your car.




OBDO = n/a
OBDI = D22
OBDIIa = D11
OBDIIb = C18


your multi meter should beep and read short or 000.0ohms.



STEP 2

make sure the Ignition is off and unplug the EGR Connector and the ECU Connectors for this test

Continuity test between EGR Lift Pin 3 and ECU, Connect your Red multi meter lead on the EGR Pin 3, Back probe* the Black multi meter lead on the ECU Pin below that suits your car.





OBDO = n/a
OBDI = D19
OBDIIa = D4
OBDIIb = C19



your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.


If all test pass and you still get code 12 after resetting the ECU, ensure the vacuum line from the EGR solenoid is not blocked or unplugged or Replace the EGR solenoid on the LH shocker tower.

* Notes

KOEO = Key On Engine Off

KOER = Key On Engine Running

Back probe the sensor, use a paperclip and push it into the connector then touch/clip your multi meter lead to the paper clip

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!