Have a xk8 with a P1609 code,Internal control module CPU to CPU communication error. Wondered what I should do?

 

Pay some mechanic to diagnose it. If you want to do it yourself, you need to find diagnostic steps and follow them.

 

Does the workshop manual not have any info? Normally it lists the possible causes and usually provides detailed ways to test.

 

Thats not good. The code P1609 is for an internal microprocessor failure. There are two things it can be, a faulty ECM or a shorted to ground wire on ECM wire going from the ECM to the data link connector. The wire is pin 3 (pink) at the 16 way grey connector on the ECM. Make aure that the wire is not shorted to ground. If it's not then disconnect the negative battery cable for 10 minutes, clear the code and see if it comes back.

Just google all the above. I am sure there is lots of info out there that can explain it better than me.

Let us know how you get on wont you?

 

Can't see much out there about this: there's a Jaguar TSB about troubleshooting it, but it's essentially saying what frankc has noted above. There's an extra check on the fuel pump relay line, but that may be MY-dependent. What year is the car?

On Gus' site of everything here:
http://www.jagrepair.com/images/TSB/...609%20test.pdf

Good luck

 

I would delete the code and see if it comes back.

 

Hi rontnm,

P1609 could possibly be caused by clumsy insertion of an OBDII scanner plug into the Data Link Connector. Had you had the codes scanned recently?

If the code recurs after clearing it as RJ suggested, both of the wires involved pass through connector EM1, a white 20-way connector in the engine bay near the right hand enclosure. Contamination of that connector or damage to the wiring harness could trigger P1609.

Cheers,

Don

 

Found out what it was, the battery was 11 years old and starting to fail. Replaced it an cleared the error and never came back.

 

Result!

 

Rontnm,

11 years is very good going for a battery. With this interval for you, it's probably a good time to refresh the battery cables, both positive and negative, and meticulously clean both ends, with grit paper and contact cleaner. Plus the receiving contact terminal surfaces. 5min job.