Mercedes-Benz bulletin LI83.30-P-079850

Complaint Customer states the AC either does not cool/has poor performance or heat is insufficient. Cause Many possible root causes Remedy *Note - This Li does not apply if there are other Li's that apply to your concern OR you have a fault and/or guided test that leads to a root cause. AC Diagnosis (General) Initial Steps Verify Customer Concern • Confirm the issue reported by the customer. Compare to Like Vehicle • Determine if the behavior is normal by comparing with a similar vehicle. Determine Your Game and Players • Identify the diagnostic strategy and involved components/systems. Testing • Perform relevant diagnostic tests. Refrigerant Quantity • Record the amount of refrigerant recovered and compare it to the specified value (if applicable). • Forming Gas is the ONLY approved leak test method. (DYE is NOT approved) TIPS Case Submission Requirements/Warranty Claim Submission Requirements (Template attached to be used for submission of Warranty claim and/or TIPS case) Cooling Capacity Test (If System Has a Charge) *Note - TIPS case is only required if the root cause is not identified or other Li's/documents require a case to be open. Before Repairs Gauge Readings • High and Low pressure readings (from machine or separate gauges). Leak Detection (if applicable) • PPM of any leaks found. XENTRY Printouts • Climate control AVs. • HV compressor AVs (for heat and AC systems). Thermometer Readings • Left and right dash vents. • Center vent, footwell, and/or rear vents (if concern is localized). Ambient Conditions • Temperature and humidity from OCP AVs (if available). After Repairs Gauge Readings • High and Low pressure readings before and after repairs. Thermometer Readings • Left and right dash vents before and after. • Center vent, footwell, and/or rear vents before and after (if localized concern). Documentation • Complaint Analysis, Game/Players, and Testing Steps. • Include expected results and technical justification for the diagnosis. • Avoid listing R/I steps—focus on diagnostic reasoning and root cause. • All prior measurements need to be documented on the repair order. OP code usage: 831232 - Max .5 for Cooling Capacity Test 831040 - Only to be utilized if you have a fault code and are actively diagnosing that fault code (MAX 1 hour) 831762 - This includes basic leak check 831285 - This can only be used in extenuating circumstances where a leak ca

Owners of the 133 model years this bulletin names have filed 3,655 complaints with NHTSA since 2015. 65 of them name Visibility/Wiper — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.

On the 2016 Mercedes-Benz C-Class, the 15 owners who gave an odometer reading for Visibility/Wiper reported it at a median of 40,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.