Plumbed up a temporary air intake to fire the beast up - after sitting on the floor for 3 years the engine fired right up and settled down to a steady 650 rpm idle. I have a Restricted Performance message - the only code showing is P0332 Knock Sensor 2 Circuit - Low Input (Bank 2). Checked the manual and there are only 2 steps - unfortunately step 1 is remove supercharger. Before going there I thought I'd check if this is a common failure and cause for Restricted Performance. The donor was a totaled 2001 X308 with 70k miles - running/barely driveable and showing no codes at the time. Appreciate any thoughts.

 

Does checking the connector require supercharger
removal? If not that is the first place I would go.

If yes, then trace the cirecuit from the ECU as far
as you can go. Perhaps reseating the connector
at the ECU.

If removing the supercharger, the usual advice is
to replace both sensors and both hoses while
you are there. Also drain and refill the supercharger
drive oil.

Oh, are you on a fully charged battery and seeing
> 13V at the ECU?

 

I was going to drive my 1999 X308 the other day and I got the RESTRICTED PERFORMANCE message and P0327. I grabbed a good used one (SPARE), wrapped it up in a shop rag and plugged it into the harness connector at the thermostat tower.

I started the engine and the message disappeared so I replaced the KS (Bank 1) with a 13mm socket through the intake runners. The NA engines are easy to replace the KS because of the plastic runners giving access to the fasteners. You just 'fish' the wire harness to the connector and you're done.

The SC KS are difficult to replace but you can just plug a new one (or known-good) into the connector and wrap it up so it does NOT 'bang-around' to verify that the fault is with the sensor itself. The RESTRICTED PERFORMANCE message should not be displayed once the fault is rectified.

bob

 

Bobs - thanks for the tips - will let you know what I find.

 

Just noticed in another thread about intercooler cleaning
that the connectors for both sides lead out to the front
timing case area. You can definitely reach and reseat
them, and of course do the known good subsitution as
suggested by Motorcarman.

 

Checked battery voltage, KS wire continuity back to the ecu, reworked all plug connections, and finally plugged in a new KS all to no avail - knock sensor bank 2 and restricted performance codes keep returning. One of the local jag specialists in my area who knows my project suggested the problem might be transmission related - specifically the adjustment of the J gate selector relative to the transmission. He said even a slight misadjustment can cause the trans computer to throw all sorts of codes including the ones I'm getting. The selector is aligned with park and the various gears, and I tried adjusting the cable in both directions slightly but no change in codes. Any thoughts will be appreciated.

 

Don't know if this applies to the SC engine, but I did have an issue for about a month with my NA VDP. I kept getting a CEL/RP due to faulty knock sensor bank B, so I replaced both knock sensors and it went away for a bit, but then also kept getting RP mode due to a few faulty ignition coils. I am curious if the issues wasn't some how strangely connected. I am thinking the RP mode comes from the faulty coil (without throwing a code) and the CEL is from the KS?

Just something to look into. But the good news, the KS for these cars are CHEAP! (Unless you buy the old barrel type, which I have not seen on one of these vehicles). The ones this car uses are only about $30.00 at AutoZone for OEM replacement from DENSO (come in an AcDelco box). But I would start by checking all of the connections before taking off the S/C.

My RP mode ended up being due to faulty coils. Before you tear off the SC this may be something to check into. As far as I know a faulty KS SHOULDN'T cause a RP mode.

 

Funny that you'd mention faulty coils - what popped up but a missfire/faulty coil code on 2 cylinders along with some internal knocking sounds I can't figure out. The engine has gone from smooth and quiet (albeit with a RP message) to a beast - with no intervention! I suspect something other than knock sensor or coil is going on here but damned if I know what it is.

 

Did you do a compression test before installing the engine? When I purchased my first Jag it was a 01 xjr. On occasion it had a ticking sound in the engine. At this time I knew nothing about these cars. I thought it might just be in need of a valve adjustment. Well I was wrong and it turned out to be dropped valve seats from overheating.

I hope this is not your case but if you can't find any other solution do a compression test to see if one or more cylinders have low compression.

 

Hello all together,

I'd definitely check the coils! I had the same (KS-related DTCs, restricted performance mode, CEL) and replaced both knock sensors. Had to pull the supercharger etc etc. After all, nothing changed! I even checked the timing etc and renewed everything I came along. In the end one faulty coil was the culprit without having any coil-related DTC.
So before you start tearing off the intake system and the supercharger, get one or two used coils off ebay, swap them around and read the codes
Best regards, Alexander

 

Thanks for the coil advice. I noticed the coil harness plugs are adjacent to the knock sensor plugs that I've been fooling with and sure enough - a simple disconnect/reconnect of the coil plugs returned the engine to its former smoothness. Still have the restricted performance and knock sensor codes. I'm wondering if the RP could possibly be related to the control modules in the doors - these aren't installed yet and I'm wondering if that could be the cause?

 

In my opinion it's unlikey being the door modules. I see no obvious reason for this.
Do you get only DTC P0332 or others as well? Does the codes change when you entirely disconnect the knock sensor?

Maybe you can track down your problem when getting an used and working knock sensor off ebay and temporarily attach it somewhere else to the cylinder head (say e.g. with a strong zip-tie at the hook-eye of the cylinder head located close to the temperature sensor of the coolant outlet pipe). Maybe then the codes will change.

Otherwise run the pinpoint tests mentioned in JTIS to rule out a short or a fouled wiring from the ECU to the sensors.
Best regards, Alexander

 

Alexander, I had already plugged in a new knock sensor so knew that wasn't the problem. Thanks for mentioning the pinpoint tests in the manual - I had never run across them before. I had already done a resistance check but sure enough there was a short to ground - I jumped a wire to the ECU and the code cleared along with the restricted performance message. I also had a camshaft position sensor fault and knew these sensors rarely fail and knew there was no problem with the cam drives or timing. Sure enough - another short to ground was indicated and the code cleared once I jumped the wire to the ECU. I completely forgot that I had extended the engine harness about two feet way back in the project. Despite the painstaking work (130 wires as I recall) a soldered strand of wire had penetrated the shrink wrap on those two leads and was shorting. Thanks again everyone for your assistance.