View Full Version : WIF/AIT/MAF

03-18-2011, 04:23 AM
Our 2008 NCV3 is in at MB for some warranty work. The CEL and WIF lights are up. Analyzing the CEL indicates AIT and MAF sensor issues. MB put it on the SDS and have been checking voltage at the sensors. Apparently there is no power to or from the MAF, and only power from the AIT, but not to it. At this point they are going to replace the fuel filter sensor. I believe they feel that the fuel filter sensor is the root of the problem. Input please....:thinking:

Altered Sprinter
03-18-2011, 05:25 AM
Slowstride there are a series of tests to confirm faults if you had the code then some could give you a clearer set of definitions as to which sensor faults to look at.
Some times it can be misdiagnosed and your scan MB can give a false indicator but if in doubt Have a complete scan done rather than a quick test.
My wording has differences as to the U.S but they are the same scanners.
Changed my mind.. I feel like just doing this anyway.
The ecu is able to monitor and identify most drivabilty related trouble conditions,some circuits are directly monitored through the ECU-Feed-Back-Circuitry>In addition the ECU monitors the voltage state of most circuitry and compares those states with expected values In Australia under MB Diagnostic Assistance Systems we use Filter status All control Units via the ECU to ascertain the values and or parameters that are designated for each open circuits maximum settings, and cross reference back to match the current values for first and last where faults as stored in the ECU.
Although most sub systems of the engine control module are either directly monitored, there may be occasions where diagnostic trouble codes are not immediately identified for trouble codes these are stored as stored and current or sorted followed by a the prefix of -f- = fail and or stored but not reconsidered to set followed by the leading mark http://sprinter-source.com/forum/images/icons/icon4.gif
A specific set of conditions must occur and unless these conditions occur ,a DTC will not set.
This is where the Aussies run a muck every time as to costs involved with MB Australia.
They will spend a 100 dollars just to save a buck and MB is so easy to work with ,if you work with MB and it's systems: Star is easy to understand and a wonderful tool to work with.


03-18-2011, 02:13 PM
I was hoping one of the Sprinter technicians, such as yourself, would reply. I will try and digest this information. I understand the Sprinter tech at the local MB dealer is quite good. I'll see what they come up with and take it from there. Thanks to an Aussie, from a re-patriated Kiwi. :cheers:

Altered Sprinter
03-18-2011, 11:00 PM
I'm not a technician, Just have an interest with Benz :popcorn:

03-24-2011, 09:17 PM
New WIF sensor. Bad connection at a fuse board. No more warning lights. More power, less Load, more MAP and better economy.:bounce: