Codes 0401 & 1409 on 1998 6.5 TD

[SETE]

I have been getting code 0401 everyday for about 6 months. I took it to a dealer, and he couldn't find anything wrong. He told me to drive it this way. I clear the code every few days. Now for the last month, I also get code 1409. Has anyone had this problem?? Thank You!!

[Andy Chesek]

Code 0401: EGR System Flow Insufficient

Code 1409: EGR Vacuum System Leak


First thing you will want to do is check for any loose, damaged, or restricted vacuum lines, pay particular attention to the line from the EGR solenoid to the EGR valve.

Check the EGR valve to see if it is leaking.

Test your vacuum pump.

Do you have gauges? If so, how much boost are you seeing?

[ 08-22-2005, 03:11 AM: Message edited by: 93_Burrito ]

[SETE]

Thanks 93_Burrito for your reply. I have checked the hoses and fittings. And I just checked the vacuum again. I have 17" of vacuum at idle, 22" at 2000 rpm right off the pump hose. I have between 0 to 2.5" at the EGR with thr RPM anywhere between idle and 2000. I had the EGR off a couple of weeks ago, and with the motor running, it would open and stay open, but I don't remember at what RPM. Hope this helps.
Thank You Again!!!
Steve

[SETE]

Has anyone else seen this problem, or have a solution?? Thank YOu!!

[Dimsdale]

What about the solenoid itself? I had a code set by the wastegate solenoid a while back, which is a similar setup. Seems like the most simple thing to check after the hoses and vacuum supply.

The manual says "the most likely cause of failure is a condition causing low back pressure." They list "Plugged EGR ports, Exhaust system leaks, and exhaust system modifications" as possible code setting conditions.

Most of the manual checks involve a Tech 2.

It also says that the Adaptive Learn Matrix is used to adjust the EGR vacuum control based on mass air flow (MAF), hence the involvement of the MAF sensor. This can "change as a result of back pressure increases over the life of the vehicle or other engine system variations."

Maybe a catalyst backup?

Sorry if this seems confusing, but that is a condensation of what is in the manual regarding this code.

Re: code 1409: "check the leaking or deformed vacuum hoses to the vacuum pump. Check and repair one of th following: hoses from the EGR vent solenoid to the EGR valve and the EGR pressure control/BARO sensor, or malfunctioning EGR vent solenoid."

Hope it helps! Dirt or sticking solenoids are a big problem! I would definitely check them with working/new units as a last resort.