I may have done some damage this time??? I was curious to see how the egr solenoid was working with respect to throttle position. I was testing the plug with two wires that go to it with my test light. Whe I was on the positive lead with my test light in the plug I reached over to move the throttle and the test light just nipped ground. There was barely a spark but the light went out and never returned. I should have been using my volt meter!!!

The check engine light illuminated and I read three codes:
P0100 - Mass air flow circuit malfunction
P0243 - Wastegate solenoid
P0400 - Egr flow

I believe the wastegate and egr solenoids are on the same circuit and I guess the mass air flow too.

I am wondering if I fried this circuit in the computer? I do not think there are any fuses for this sort circuit is there? I was under the impression it all ran through the computer.

I did clear the codes and they just immediately come back. The car runs ok with the exception of lack of power which I know happens when either the egr or wastegate codes come up.

Does anyone have any info on this? I am thinking at the worst an engine computer and maybe the MAF and solenoids. Thanks!
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__________________
-disav

99 E300 TURBODIESEL Astral Silver 282K - AMG brakes, suspension, monoblocks, speedo & interior - Full Load Maxed on IP by custom Speed Tuning USA Chip - T3/T4 Garrett - EGR/MAF delete
98 E300 TURBODIESEL Alexandrite Green on black leather 289K
95 E300 DIESEL Green Queen 267K SOLD
84 300D 216k SOLD
87 300D 299K #22 head - intercooler - full load adj. - 8sec 0-60mph - SOLD
76 300D 214K SOLD

At worst the engine computer? Have you priced it?

Start by checking the K40 power supply relay in the COMPUTER box. There are between 4 & 6 fuses in the power supply relay.

It is located at the right rear of the engine compartment..you have to un-screw the cover..good luck.

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MERCEDES Benz Master Guild Technician (6 TIMES)
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190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks M.B.DOC!! There was a 10A out where you said. I am relieved.

__________________
-disav

99 E300 TURBODIESEL Astral Silver 282K - AMG brakes, suspension, monoblocks, speedo & interior - Full Load Maxed on IP by custom Speed Tuning USA Chip - T3/T4 Garrett - EGR/MAF delete
98 E300 TURBODIESEL Alexandrite Green on black leather 289K
95 E300 DIESEL Green Queen 267K SOLD
84 300D 216k SOLD
87 300D 299K #22 head - intercooler - full load adj. - 8sec 0-60mph - SOLD
76 300D 214K SOLD