I have a 99' XK8 Convertible with 84k miles on it. A few weeks ago I was cruising on the freeway when I got on the throttle a little to pass someone. All the sudden it hesitated & I couldn't go anymore. I couldn't get over 5 mph. It would still run but it idled real rough & choppy. However, it did not overheat & all the fluid levels were still good.
I plugged in my little diagnostic device & got two codes.
The first code was 1642- CAN Circuit Malfunction.
The other was for a Random Misfire, I can't remember the number.
Any suggestions or advice would be very welcome and appreciated. Thanks!

 

More knowledgeable Forum members will chime in, but as far as I'd say the Can Circuit Malfunction isn't your problem, respectively the reason for your engine issues.

More common are misfires due to water or oil around the spark plugs. Easy enough to check.

Good luck,
Chris

 

Unfortunate that you can't recall the other code(s).

P1642 - CAN cicuit malfunction is either:

1. CAN short circuit fault
OR
2. Control module failure

With (2), the additional code(s) help to locate the control module source.

Provided you are using a compatible reader and the codes can therefore be relied on, read them again and post back.

Once I've noted stored codes, my approach is usually to clear them and run the vehicle to see if they set again. Often they won't because in many cases all it takes is a temporary out-of-range voltage on a sensor to set a code.

Graham

 

For a clearer picture I would suggest reading ALL the modules especially the ones on the CAN bus. A generic reader will NOT be able to read the TCM, INST PK and ABS.

The Selector Lever Module is also on the CAN bus but it is a 'listen-only' node on the network so it won't report DTCs.

It could also be a wiring fault. The network cable is a 'twisted-pair' (40 turns per meter Blue and Yellow).

I remember one time an X100 came into the shop with a broken CAN harness in the right rear area where the conv top hydraulic lines are routed. Someone probably changed the lines and damaged the twisted pair. (YANKED ON THE HYDRAULIC LINES??????? still cable-tied to the harness)

The other repair shop could not figure out the fault.

Pins 6 and 14 are the CAN bus wires in the OBDII connector. One should have slightly more than 5 volts (CAN HIGH) and the other should be slightly less than 5 volts (CAN LOW). You should also have a terminal resistance of about 60 Ohms across the pins 6 and 14 (battery disconnected) if the network and/or wiring is intact.

I see more diagnosis in your future.

bob