I am chasing a problem with my 2000 XK8 4.0 liter, going into restricted performance. It has been in storage and the KTM fuse was loose so I had a lot of codes including P1260. when I revived it, it was in restricted performance. Codes were misfires on cylinders 1-5. I cleared the codes to get rid of old ones and started it to see if I got the same misfires. After idling I got a gearbox fault and it felt like it was misfiring. Only code, other than an AC pressure switch fault, is P1795, inconsistent CAN Level, previous to the gearbox fault I was getting ABS and Traction control messages on the dash. I am an avid "to the garage" fan and have seen posts about repairing the abs module. I will be checking the resistance at the ABS Module today to see if the CAN circuit is good from the ABS module forward. Am I chasing my tail? Is there something else I should look at?

 

Regarding the gearbox fault, often the ATF is leaking into the electrical connector. The connector should be replaced, but at a minimum cleaned with CRC electrical spray cleaner and replace the sealing o-rings.

the connector is held in place by a single captured bolt with an 8 (??)mm head. Do not overtighten !!!

Z

 

Hope I don't sound dumb, but which connector? Where?

 

Concerning restricted performance and the gearbox fault (Also, may pertain to wrong part fitted when it is indeed the correct part)
I would rear probe (connector NOT disconnected) the TCM +12v connector with VOM. If less than 12 volts, I would check for a faulty / intermittent connection anywhere along that circuit that could rob the TCM of its full 12volts. (one place in particular, the underside connections of the driver side under bonnet fuse box)
Such gearbox faults may not necessarily trigger any DTC's.

 

Battery was a little low so I charged it and cleared the codes. Started right up, ran great for about 0.2 miles and started missing. Resistance between pin 6 and 14 was 61.3 ohms. Checked codes P1795 gone. Now have P0353, ignition coil C primary/secondary circuit malfunction. Gearbox fault cleared, came back, cleared again so I will look at and clean the connector once I find it. Maybe the P1795 was due to the low voltage. The coil message certainly would cause the missing. No codes showing which cylinder(s) is/are missing

 

Steps in order I would take are:

1) make sure battery is fresh and charging.
2) tighten all ground points and make sure main fuse in trunk is secure and not loose.
3) tighten positive contacts on fuse assemblies. Reseat all relays and replace generic with oem equivalent.
4) clean all connections on Ecu, tcm and fuse assemblies with electrical contact cleaner. Remove all corrosion.

 

It’s the cylindrical connection at the bottom of the transmission.

 

Workshop manual said P0353 related to cylinder 5 so I switched coils for 5 and 6 and started it up. Still getting restricted performance and gearbox message and after running it more it warmed up and in addition to p0363, I now have codes showing misfires on 1-4 and p0300 random misfires multiple cylinders. I'll come back to it tomorrow and check all my connections as suggested above.

Thanks for all the input

 

I think that your workshop manual is in error. P0353 relates to cylinder #3 rather than #5.

 

For some obscure reason, Jaguar renumbered all the cylinders for the 4.2, so, if you get the wrong layout diagram, cylinder 5 is in the same place as cylinder 3



Thankfully, the P-codes are correct wherever the cylinder may be...

to the OP - It appears you have a faulty coil pack, note that a dud one can affect other cylinders in the same group

 

I would read the CHASSIS DTCs before going down the ABS 'rabbit-hole' with unnecessary tests and repairs.
The module has the DTCs to tell you where to look. Hopefully it was just a low voltage problem?

 

Well that explains why I thought it was #5. I'll switch #3 with one on the left bank tomorrow and see what I get. Thanks

 

Probably to match international standards including OBD II numbering.

 

Cleaned connections as recommended by 2500dollar xkr, thanks to michaelh I switched my #3 coil with #5 and the dtc went from p0353 to p0355. So I will replace that coil and hopefully that clears up the misfires. Now on to the gearbox fault and replace O-rongs on the transmission connector as recommended by zray. Thanks to everyone for your help

 

Thanks again. I replaced the coil pack and drove it up the road. No restricted performance and strangely enough now gearbox fault. That may come back although I still plan on replacing the o-rings on the connector.