Mods, might want to add this to a sticky, if you think suitable 
OK, so why am I always on about SDS and even if you don't want to buy your own why am I always saying to INSIST an Indie with SDS (or Dealership) give you a Print Out ?
Read on .............
Background, a local guy has an A Class 180 CDI, had it less than a year, it's a proper horror, but he needs an MOT and Engine MIL Light is on, so here it is in my Workshop for a Diagnosis because no - one else can find what is wrong with it ..................
So here is SDS at it's finest, with an Operator, (me 🤣 ) who has half a clue how to use it .....................
I blocked out my Workshop Details because I don't want half a million telephone enquiries about what I think is wrong with folks cars, so anyone reading it please post up here on forum then if I can I will advise you and also anyone else reading will benefit
First (Initial) Code Read, All Modules, lots of codes ....
So after Printing and Saving that all Modules Test we delete everything then Road Test it, in this case I let it get completely Cold, (will then retest Glow Plugs), then re start and do a second (and in this case) Final Code Read ....
You can now see that a lot of the Codes have gone They were old codes / events that were stored from previous meddling or repairs by somebody
I am really only concerned with the Engine MIL issue right now, but I can also advise the guy that he needs 4 new Glow Plugs and a new Anti Theft Alarm (ATA) Siren.
But they are not what is causing the MIL, Glow Plugs just hold on the Glow Plug Light on these CDI Motors, and ATA will not put Engine MIL on either, so duly noted on his Print Outs and lets move on
We have a Code indicating Fuel Rail Pressure, SDS is telling me that the pressure is Low even when the Rail Regulator Valve is closed .........................
That is a Code, because an awful lot of things can cause that ............................ I don't just want to chuck Rail Regulator, Rail Pressure Sensor, Quantity Ctrl Valve or Injectors at it, so lets go further .....................
So I double click on that particular Fault Code and it leads me down a Rabbit warren of Testing, first was to Graph the Quantity and Pressure Control Valves, if Pressure goes above certain figures which SDS tells me, there is a Fault, it didn't therefore there wasn't a fault with those 2 items ....
Second test SDS leads me too is the Low Pressure Fuel Supply circuit ............... the Fuel Pressure (Bar) with a Gauge at Filter Inlet Pipe, then Test Fuel Supplied (ml) at Filter Outlet which all passed with flying colours.
Third Test is the correction factors on the 4 Injectors, which also passed but look at it's correction figures, they are much nearer end of scale than Cylinder #1, there is a clue in that because the correction factors are doing their best to run 3 of the cylinders smoothly ....
No surprises "Sherlock", SDS now asks me to do a compression test ....
Number 3 Cylinder is well low, and Numbers 2 and 4 are a wee bit lower than Number 1, who's Injector is not getting near it's end of correction scale !!
I could remove the Glow Plugs and whack a Compression tester on it, but having driven it, and listening to it crank over erratically I will advise the Guy not to waste his money going any further with it
So my customer gets to pay me for 3 hours of fairly involved Diagnosis, but he hasn't had to chuck umpteen parts and labour trying to flog a dead 'orse and he gets an explanotory Print Out of various relevent Codes, Tests and Results, plus my opinion on his best option
Although this Car is an A Class CDI, SDS does of course do guided testing on all MB Cars, pre 2000's MB's are not covered as well, but it still does it
So, this is exactly why SDS is way way more than just a fault code reader / resetter and oh so much better than all the others, and helluva good price really for what y'all get
HTH
OK, so why am I always on about SDS and even if you don't want to buy your own why am I always saying to INSIST an Indie with SDS (or Dealership) give you a Print Out ?
Read on .............
Background, a local guy has an A Class 180 CDI, had it less than a year, it's a proper horror, but he needs an MOT and Engine MIL Light is on, so here it is in my Workshop for a Diagnosis because no - one else can find what is wrong with it ..................
So here is SDS at it's finest, with an Operator, (me 🤣 ) who has half a clue how to use it
.....................I blocked out my Workshop Details because I don't want half a million telephone enquiries about what I think is wrong with folks cars, so anyone reading it please post up here on forum then if I can I will advise you and also anyone else reading will benefit
First (Initial) Code Read, All Modules, lots of codes ....
So after Printing and Saving that all Modules Test we delete everything then Road Test it, in this case I let it get completely Cold, (will then retest Glow Plugs), then re start and do a second (and in this case) Final Code Read ....
You can now see that a lot of the Codes have gone
They were old codes / events that were stored from previous meddling or repairs by somebody I am really only concerned with the Engine MIL issue right now, but I can also advise the guy that he needs 4 new Glow Plugs and a new Anti Theft Alarm (ATA) Siren.
But they are not what is causing the MIL, Glow Plugs just hold on the Glow Plug Light on these CDI Motors, and ATA will not put Engine MIL on either, so duly noted on his Print Outs and lets move on
We have a Code indicating Fuel Rail Pressure, SDS is telling me that the pressure is Low even when the Rail Regulator Valve is closed .........................
That is a
Code, because an awful lot of things can cause that ............................ I don't just want to chuck Rail Regulator, Rail Pressure Sensor, Quantity Ctrl Valve or Injectors at it, so lets go further .....................So I double click on that particular Fault Code and it leads me down a Rabbit warren of Testing, first was to Graph the Quantity and Pressure Control Valves, if Pressure goes above certain figures which SDS tells me, there is a Fault, it didn't therefore there wasn't a fault with those 2 items
....
Second test SDS leads me too is the Low Pressure Fuel Supply circuit ............... the Fuel Pressure (Bar) with a Gauge at Filter Inlet Pipe, then Test Fuel Supplied (ml) at Filter Outlet which all passed with flying colours.
Third Test is the correction factors on the 4 Injectors, which also passed but look at it's correction figures, they are much nearer end of scale than Cylinder #1, there is a clue in that because the correction factors are doing their best to run 3 of the cylinders smoothly ....
No surprises "Sherlock", SDS now asks me to do a compression test ....
Number 3 Cylinder is well low, and Numbers 2 and 4 are a wee bit lower than Number 1, who's Injector is not getting near it's end of correction scale !!
I could remove the Glow Plugs and whack a Compression tester on it, but having driven it, and listening to it crank over erratically I will advise the Guy not to waste his money going any further with it
So my customer gets to pay me for 3 hours of fairly involved Diagnosis, but he hasn't had to chuck umpteen parts and labour trying to flog a dead 'orse and he gets an explanotory Print Out of various relevent Codes, Tests and Results, plus my opinion on his best option
Although this Car is an A Class CDI, SDS does of course do guided testing on all MB Cars, pre 2000's MB's are not covered as well, but it still does it
So, this is exactly why SDS is way way more than just a fault code reader / resetter and oh so much better than all the others, and helluva good price really for what y'all get
HTH
