Thank you - will get the other codes from the garage.
Their code readers would not give enough detailed info so they took it to the Chrysler main dealer for clarification.
The yaw sensor was also suspected at some point...
OK, in addition to P0500, we have C1120 & C1142 (latter subject to confirmation)
C1120 seems to relate to gearbox speed sensor.
Failing that, they say the next thing to check will be the yaw sensor.