A 2007 domestic Chrysler 300C, equipped with HEMI-5.7L engine, NAG1 automatic transmission. The car has traveled 27097km for five months, his owner came to my plant and reflected that the car trumpeted irregularly during the process of driving.
With the use of Chrysler Diagnostic Tool (WITECH VCI POD), I read the history DTC U1109 in the SCM, which means that SCM lose communication with LIN steering wheel controls). Checking the lines, I found no abnormalities and analyzed the fault has nothing to do with this. Because the loss of communication with the steering wheel controls only causes no sound, not automatically trumpeting. So I replaced a SCM and then returned the car. Three days later, after telephone interviews, customers reflected all works normally. I thought that the fault has been resolved.
However, another day, the customer came again, he said the things got worse. The trumpet not only made automatic sound but also no sound when honked the horn sometimes, which in turn, leading to failures of multi-function switch on the steering wheel. The frequency of failure was high. Chrysler Diagnostic Tool again read U1109, then I tested and found that trumpet and multifunction switch can’t work when the steering wheel came to certain angle. I doubted the problem lies in clock spring, then, I replaced the clock spring, and trouble was removed.
Chrysler Diagnostic Tool (WITECH VCI POD)