W202 P1570 DAS Fault - Solution
 

Greetings,

Occasionally, I assist a few friends, who own repair shops in and around Los Angeles, with difficult/unusual problems. Recently, I was asked to look at a 6/1996 production (1997) C280 with an unusual problem.

This car would crank for approximately one second and stop cranking. Codes retrieved were P1570 DAS Fault. A second key was ordered prior to my involvement. The new key produced same results.

Upon initial inspection, all fuses (all 3 locations) were verified as intact. STAR diagnostics were used to examine the systems. All indications pointed to a bad DAS control module. On a 1997 W202. there are 2 possibilities for the DAS module in the 1997 model year. This had the smaller DAS that did not have the integrated RCL, (MBZ #210.820.32.26)

After the DAS was installed, the car started for about 3 seconds and died. It then continued the cycle of crank for approximately one second and then stops.

STAR was again used to check the actual values and a CAN fault was found in the DAS. I also noticed that door and trunk lock function had mysteriously ceased after the car died.

Inspection revealed that fuse #27 in the LF engine compartment had a hairline fracture that was visible only under magnification. Replacing this 15 amp fuse brought door locks back online and resulting in engine start every time.

It is unknown if the fuse was the cause of the issue, or it was the DAS module at fault all along, but we replaced the DAS anyway, since it isn't very expensive...less than $600.00 brand new from MBZ Fort Worth Texas.

Hope this information is helpful....

In addition to the 97 SL320 I have a 97 C280, both use the same system.

This is interesting, 1997 DAS with chip in a key doesn't affect cranking, it shuts off the fuel injectors after 3 seconds _if_ the DAS box does does not see a valid key / ECM does not see a valid CAN message from the DAS box. Older non chip key systems did interrupt the starter of the .

I'd say the non crank was brought about by the general module going down. ( in the right hand under hood computer box, the large purple wire is starter trigger. ) and somehow the DAS box was not completing the chip read / compare / write new code to key.

Very late 97 ( 7-97 I think ) / early 98 had a bunch of modules on the CAN network, the older 97 are more hard wired.