Thread: 12 Volts to EGR

2001 Gran Prix GTP L673800 with supercharger.


This is my first post,normally I have been able to read posts from others and figure out my problem.


Have been getting an occasional P1404 code, EGR Stuck open. After a long process of trouble shooting I discovered that the connector to the EGR valve pin E (EGR solenoid high control) has 12 volts when disconnected from the EGR but the 12 volts is not present when connected.


This is a list of things that have been done so far.
a) Changed the EGR with a spare that I had, this did not resolve the problem, then discovered that the 12 volts checks OK with the connector removed from the EGR using an ohm meter but when using a test lamp the 12 volts is not present. I realize the ohm meter does not put a load on the circuit and the test lamp does.


b) Checked the wiring from the PCM to EGR. Metered the wires from the PCM connector C2 pin 4 and all checks out OK.


c) Metered the voltage on the PCM connector C2 pin 4 and have 12 volts with the ohm meter and with the load of the test light the 12 volts goes away.


d) Changed the PCM with an E-Bay used unit programed for my VIN, this didn’t fix the problem.


e) Metered the PCM C1 pin 19 connector for ignition 1 voltage with the ohm meter and test light and have 12 volts. Metered the PCM C1 pin 20 battery positive voltage with both ohm meter and test light and have 12 volts.


f) Metered the PCM C1 pins 56, 57 and 60 for ground with the test light and all are OK.


Now I am starting to worry that I might be trying to fix something that isn’t broken, is it correct to assume that 12 volts should be present at the EGR valve connector pin E when connected and the ignition key on?

Any assistance would be appreciated.

Sorry for such a long post.

Yes itssupposed to have power to it then the computer controlls the stages of EGR included in the intake to reduce knock and NOX

OK thanks for the reply. I guess the next step for me is to put it back together and drive it and see if it gives me any other codes. I didn't mention that the darn thing runs fine other then the P1404 code. A few years ago I had the P1404 code and it was as simple as cleaning the EGR valve and performing the re-learn process by disconnecting the EGR harness and clearing the code.

EGR port may need cleaned out also

Thanks Monza Racer,
I checked the EGR port and it is clean, did this before I realized that 12 volts to the EGR was missing when the plug is connected to it. I am starting to think that another sensor is pulling the voltage down but am still piddling with it. It still confusing that with the connector disconnected from the EGR I have 12 volts with a ohm meter but when checked with a test light no voltage.
Thanks for your input.

So this is from a "learned" position. Consider unhooking battery for overnight and making it relearn the position. Maybe a bit of a stretch, but maybe it's learned a bad position.

BillBoost37,
I took your advice and disconnected the battery overnight after putting everything back to original. Just about wore out the car driving it around to get the PCM/ECM back to a ready state, couldn't drive through all of the conditions required due to construction, traffic and wrecks. Have only driven it about 60 miles so far after it flashed ready but no codes yet. Will update after it gets driven a bit more.