Hi all,
2007 CL600 M275 5.5
I'm having an issue which I am struggling to diagnose. First thing I should point out is there are no codes stored on any of the cars modules. Both batteries in the car are only 6 months old.
The issue is that, once warmed up, and coming to a stop the car will return to idle, after about 4-5 seconds of perfect idling the voltage suddenly drops to 11.8v before immediately recovering. This causes a noticeable change in the engine tone and sometimes a little shake. Once it happens everything seems to return to normal and it won't happen again on the journey or subsequent journey on a given day.
Attached are some data logs. The columns are (Time, Voltage, RPM, Fuel Pressure, Throttle Position, Manifold Pressure). As you can see the fuel pressure, throttle position and manifold pressure all remain stable so I don't think it is a fuelling issue, vacuum leak or throttle body issue.
Any assistance very much appreciated.
2007 CL600 M275 5.5
I'm having an issue which I am struggling to diagnose. First thing I should point out is there are no codes stored on any of the cars modules. Both batteries in the car are only 6 months old.
The issue is that, once warmed up, and coming to a stop the car will return to idle, after about 4-5 seconds of perfect idling the voltage suddenly drops to 11.8v before immediately recovering. This causes a noticeable change in the engine tone and sometimes a little shake. Once it happens everything seems to return to normal and it won't happen again on the journey or subsequent journey on a given day.
Attached are some data logs. The columns are (Time, Voltage, RPM, Fuel Pressure, Throttle Position, Manifold Pressure). As you can see the fuel pressure, throttle position and manifold pressure all remain stable so I don't think it is a fuelling issue, vacuum leak or throttle body issue.
Any assistance very much appreciated.