P0400 - Solution not so obvious

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Apr 21, 2012 | 12:45 AM

#21

avos

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Joined: Apr 2008

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From: Europe

Vacuum drops when the EGR opens, and the EGR only operates when driving. Even with the IDS it wasn't so obvious to see, and it is a very short timeframe. Personal I would focus on getting the vacuum right, then see if the issue still persist, and go from there.

Apr 24, 2012 | 09:48 PM

#22

DrkNyte

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Joined: Dec 2011

Posts: 104

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From: El Dorado Hills, CA

Quote:

Originally Posted by avos

From memory, the vacuum line goes to the actuator (bypass valve for the supercharger), to the Evap system and MAP sensor. You can check the actuator if that one could be leaking but I am not sure how the EVAP works and if a leak there could cause any issues (you should find it in JTIS, there are some diagrams iirc). Ideally you should measure the values of the MAP sensor that can be compared here with other cars. As I don't have a MAP sensor, I can't give you a reference.

I tested the Actuator for the Bypass Valve. It will not hold a vacuum. I also tested the line going into the actuator. When it's connected I checked the vacuum for the line going to the MAP sensor. It reads 12 in. Hg. When I take the reading fome the line going to the Actuator it reads 17.5 - 18 in Hg. so it is definitely the Actuator. Now I need to get the Part.

I need to get a Part number for just the actuator can anyone help? The valve shows up evertime I do a check for Part Number. Also is there a download for the partslist? I didn't find it on the JTIS.

Thanks!!!!

Apr 25, 2012 | 02:10 PM

#23

DrkNyte

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From: El Dorado Hills, CA

As it turns out this is a dealer only Part (NCC7703AC) at a cost of $175.89 form the nearest Jag dealership

Sep 3, 2013 | 01:19 AM

#24

Big-D

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Joined: Jul 2013

Posts: 53

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From: PLUMAS LAKE,CA.

There has been long time since any replies.
The egr in my 1995 xj6 4.0l x300 has a egr temp sensor that actuates the egr valve thru ecu and mine ic bad giving misfires and carbon buildup on plugs and o2 sensors. It runs good for about 8 miles then gives hicups and stalls and goes into limp mode. The sensor is open circuit about 1.2 meg ohms. Ordered an egr temp sensor they are not cheap. Lowest price about $!49.99

Feb 8, 2021 | 11:01 PM

#25

Hazmat1075

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Joined: Jan 2021

Posts: 31

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From: Rancho Cucamonga, CA

Hi what do you mean Don't try to start with a booster, you will fry the electronics.. Just wanted to know in case.

Feb 9, 2021 | 09:35 AM

#26

Don B

Joined: Feb 2014

Posts: 20,472

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From: Crossroads of America

Quote:

Originally Posted by Hazmat1075

Hi what do you mean Don't try to start with a booster, you will fry the electronics.. Just wanted to know in case.

Hi Hazmat1075,

This thread has had no activity since 2013. Check your Driver's Handbook and Vehicle Care manuals for details on jump-starting your car.

Regarding the admonition against using a "booster" to jump-start a Jaguar, I believe the manual is referring to the self-contained battery-pack or capacitor style emergency jump-starting units carried by tow-truck drivers and other service personnel. However, I have a professional battery-pack unit that works fine on Jaguars. It's the JNC Air 1700 Amp JUMP n Carry and also includes an air compressor for inflating tires. It has "smart" circuitry to protect from reversed cables, over-voltage, etc. I have used it on many Jaguars with no problems, but your mileage may vary.

Cheers,

Don

Last edited by Don B; Feb 9, 2021 at 10:25 AM.