Post by gkevinq on Jul 23, 2019 21:01:42 GMT -5
Hello all, there's currently a problem with EGR solenoid circuit on my 2001 MS not controlling the solenoid properly.
Recently got this car from my uncle and it had the P0403 code. I checked the circuit for the egr solenoid and sure enough something was wrong. One of the wire, the yellow one, was exposed and directly connected to a wire that's connected to a ground. I took the extra wire off and cleared the code and it went away.
Right away, I noticed that the idle is rough compared to when the ground was connected. I drove the car smoothly, except when idle, about 40 miles and the service engine light did not come on; instead, I checked the codes again and got P0401 pending code. I also noticed that when there's traffic and I'm on idle for an extended amount of time, the car starts to overheat and as soon as I start driving it cools down.
I came back home and I tested the EGR valve, vacuum control valve, and the solenoid and they are all working as per the manual. Then I tested the solenoid connector and it is providing battery voltage on the red wire and there's continuity from the yellow wire to the PCM. The only thing I noticed is that when the car is on, or on idle, it does not seem to close the EGR solenoid and this is probably why it's causing the idle to run roughly. From my understanding, the solenoid should be closed when the car is on or idle. When I connect the ground wire back to the exposed yellow wire, I can hear the solenoid click and the engine starts to run smoothly. I also tested that with the ground connected, it does hold vacuum and does not when it is not connected. The only issue is that the P0403 code comes back when the ground wire is connected.
In the end I concluded that the problem lies with the PCM not working properly, but I'm not too sure. Is there a way to test the egr function from the PCM? Or could the issue be something completely different?
Also how does the PCM control the solenoid? Does it provide ground to close the solenoid?
I currently don't have the funds to buy those expensive test equipment and or just replace the PCM, so I'm looking forward to your inputs.
Thanks in advance.
Recently got this car from my uncle and it had the P0403 code. I checked the circuit for the egr solenoid and sure enough something was wrong. One of the wire, the yellow one, was exposed and directly connected to a wire that's connected to a ground. I took the extra wire off and cleared the code and it went away.
Right away, I noticed that the idle is rough compared to when the ground was connected. I drove the car smoothly, except when idle, about 40 miles and the service engine light did not come on; instead, I checked the codes again and got P0401 pending code. I also noticed that when there's traffic and I'm on idle for an extended amount of time, the car starts to overheat and as soon as I start driving it cools down.
I came back home and I tested the EGR valve, vacuum control valve, and the solenoid and they are all working as per the manual. Then I tested the solenoid connector and it is providing battery voltage on the red wire and there's continuity from the yellow wire to the PCM. The only thing I noticed is that when the car is on, or on idle, it does not seem to close the EGR solenoid and this is probably why it's causing the idle to run roughly. From my understanding, the solenoid should be closed when the car is on or idle. When I connect the ground wire back to the exposed yellow wire, I can hear the solenoid click and the engine starts to run smoothly. I also tested that with the ground connected, it does hold vacuum and does not when it is not connected. The only issue is that the P0403 code comes back when the ground wire is connected.
In the end I concluded that the problem lies with the PCM not working properly, but I'm not too sure. Is there a way to test the egr function from the PCM? Or could the issue be something completely different?
Also how does the PCM control the solenoid? Does it provide ground to close the solenoid?
I currently don't have the funds to buy those expensive test equipment and or just replace the PCM, so I'm looking forward to your inputs.
Thanks in advance.