Hi, I've read a lot about this issue on this forum so I decided to sign up...
I have a 2007 Citroen Jumper 3.0 with the famous P0638 code. Went to the dealer and he offered a replacement for 700€. I decided to do it myself so I ordered a Pierburg replacement.
I dismounted the old unit and it was completely corroded. I tried refitting it and testing it using 12V supply and Arduino generating a PWM signal but it seems to have some failure anyway (the valve still kicks back to the open position and then starts beeping continuously)...
Anyway I fitted the new part this weekend, but to my surprise the MIL came on right away. The engine starts but runs in limp mode. There seems to be no movement going on in the valve... I disconnected the battery for several hours and removed the error code using Car Scanner on my phone, code comes back right away... I removed it again and tested in on the lab bench using same methods as the old one: it doesn't do anything, no current draw, no movement, no resistance when moving the valve. And the status pin 4 is not connected on this newer unit.
I'm thinking the new unit may be faulty as well...
I ordered another new Pierburg throttle body today together with the newer cable connector from another store, which I can send back no questions asked.
I'm wondering if I did something wrong. On the signal pin 1 from the ECU I measure 3.75V DC and no PWM signal (I checked with an oscilloscope)
All help is greatly appreciated!
I have a 2007 Citroen Jumper 3.0 with the famous P0638 code. Went to the dealer and he offered a replacement for 700€. I decided to do it myself so I ordered a Pierburg replacement.
I dismounted the old unit and it was completely corroded. I tried refitting it and testing it using 12V supply and Arduino generating a PWM signal but it seems to have some failure anyway (the valve still kicks back to the open position and then starts beeping continuously)...
Anyway I fitted the new part this weekend, but to my surprise the MIL came on right away. The engine starts but runs in limp mode. There seems to be no movement going on in the valve... I disconnected the battery for several hours and removed the error code using Car Scanner on my phone, code comes back right away... I removed it again and tested in on the lab bench using same methods as the old one: it doesn't do anything, no current draw, no movement, no resistance when moving the valve. And the status pin 4 is not connected on this newer unit.
I'm thinking the new unit may be faulty as well...
I ordered another new Pierburg throttle body today together with the newer cable connector from another store, which I can send back no questions asked.
I'm wondering if I did something wrong. On the signal pin 1 from the ECU I measure 3.75V DC and no PWM signal (I checked with an oscilloscope)
All help is greatly appreciated!