2001 XJR, about 163,000 miles on it. Had some issues with the pedal position sensor off and on that eventually just went off and no more on (meaning the engine running right), so I took the car out of service, removed the throttle body and sent it off to ASI for a rebuild. Mine got broken in shipping, Fedex decided it wasn't their fault and denied my insurance claim. ASI was nice enough to send me a rebuilt one off the shelf for no extra charge. Got it installed, had to fiddle with the TPS to get it to run properly, but its been trouble free for months now, until last night.

Dropped my kid off at her place and was headed home when my car went into failsafe mode. Shut it down, let it sit for 10-15 seconds and restarted, all is well again...for a couple minutes. Did it again, I limped to a parking lot, MIL now illuminated, shut it down, let it sit for a few minutes and restarted, no more drama on the drive home. MIL still lit.

Plugged in my reader and was presented with a new code, how exciting! P1229, which my code reader says is an intercooler pump fault, but I've learned to not trust the reader's listings and went to the 2001 XJ OBDII code listing and find the 1229 is presenting for a "Throttle motor control circuit malfunction", which I am interpreting as the actual stepper motor that controls the throttle body butterfly and not the TPS or PPS. I presume this motor is inside the throttle body itself and not easily serviced and might lead me to a warranty issue with ASI, but is there anything I can do here that might either clear up a likely external factor thats tripping this code, or at least further diagnose the issue myself?

I've done a bit of searching, found some threads where people were suggesting everything from cleaning the contacts on the throttle body to replacing the MAF or sending out the throttle body for repair, so its kind of all over the place. Has anyone had to address this and, if so, were you successful? If you were, what was your issue?

Thanks!

 

The listing gives you three possible reasons for this fault. I would first check/clean the pins in the throttle motor connector (round 2-pin connector). It is also worth first trying with disconnecting and reconnecting this connector a few times and see if it makes any difference.

 

Thanks MS! Will do before drivnig.

 

Follow up, been about 500 miles and no issues since then, Dirty contacts it is!

Thanks!

 

I wonder sometimes...how many of these expensive modules are replaced,
when maybe.....only the connections needed attention?

 

Probably a lot more modules replaced a long time ago and more and more connector cleanings as time goes on.

 

Years ago, my service manager for my first LR3 noted that 80% of electrical issues with Brit cars were their connectors: maybe they sit too long in the parts bins before installation or sloppy install, "but, we just pull them apart, spray them with cleaner, . . "