FIAT 500 Multi Air System Drivability Issues Related

FIAT 500 Multi. Air System: Drivability Issues Related to Lack of Maintenance

Contents: • • • Description and operation Reliability Data Factory Oil Change Recommendation Research questions Experiments and results

Accumulator & Oil chamber Upper Pumping Element Solenoid Valve Lower Pumped Element (On bottom side)

Multi. Air Operation

Consumer Reports: Predicted Reliability

Multi. Air Reliability Mopar Part 4892697 AC MULTIAIR ACTUATOR Item# 4892697 AC Dealer price: $1, 775. 00 Our price: $1, 261. 49

Diagnostic Trouble Codes • • • • P 0009 -64 P 0010 -11 P 0010 -12 P 0010 -13 P 0011 -64 P 0012 -84 P 0012 -66 P 0520 -67 P 1239 -00 P 0298 -00 P 1523 -00 P 1524 -00 P 106 A-00 P 106 B-00 VVA Blocked to Repose VVA Electrovalve Circuit short to ground VVA Electrovalve Short to battery VVA Electrovalve Circuit open Position Error VVA Speed too slow VVA Speed too high Engine oil pressure circuit Engine Oil Temperature Too Low. Engine Oil Temperature Too High. VVA Low oil pressure Oil pressure out of range – Camshaft Advance/Retard disabled Oil supply solenoid valve OFF time out of range Oil supply solenoid valve ON time out of range The new revised TSB now includes expanded symptoms with the following MIL codes: • P 1607 -00 - PCM Internal Shutdown Timer Rationality. • P 2610 -00 - PCM Internal Engine Off Timer Performance.

Factory Service Procedures

Factory Service Procedures • Change oil every 8, 000 miles or 6 months • “May burn up to 1 quart of oil per 1, 000 miles” • Crankcase capacity for engine oil is 4 quarts • Do you see a problem with these numbers?

• Research question #1: – How will the Multi. Air system react to a low oil condition? • Research question #2: – How will the Multi. Air system react if the engine oil becomes sludge?

Research question #1: How will the Multi. Air system react to a low oil condition? Test: Drain oil from the crankcase in ¼ quart increments followed by vehicle restart to identify if vehicle would have starting or idling issues related to the Multi. Air system. Result: Impressively, the FIAT 500 would start and idle with no audible or otherwise discernable differences down to just ½ quart of oil left in the crankcase. Our prediction that the system would eventually draw air and cause the engine to shut off or stumble was not accurate for start-up or idle conditions. It was not until revving the engine that the system produced a DTC for oil pressure- P 1523 -00 VVA Low oil pressure Limitation: The results for this test are limited due to the inability to test drive a donated vehicle. It is predicted that if the vehicle were accelerating, decelerating, or turning at speed, that the low engine oil level would have a greater impact on the Multi. Air system and it’s ability to perform. Catastrophic testing may be required to reach full test results.

Research question #2: How will the Multi. Air system react if the engine oil becomes sludge? Test: In order to simulate oil sludge (from lack of proper oil changes), a thicker viscosity engine oil was used. 20 w 50 was selected to replace the factory specified 5 w 30. The vehicle was dyno tested throughout a range of operating conditions with the two different types of oil. Diagnostic trouble codes were monitored along with monitoring electrical signals via an oscilloscope.

• Research question #2: How will the Multi. Air system react if the engine oil becomes sludge? • Result: Despite the tight tolerances of the Multi. Air system components, there was no observable difference in how the machine performed on the dyno, no diagnostic trouble codes were produced, and no observable differences appeared in the oscilloscope signal patterns. Limitations: It is predicted that the thicker oil may have an impact on the vehicle’s fuel economy. However, longer-term testing is needed to identify this. The research question may need to be altered slightly to say just how thick the oil can be before a more serious drivability concern will develop. More testing could be completed to identify if thicker oil impacts the power output of the engine and also the engine emissions.