S430 No crancking, No starting
 

Hi friends, after removal of the N3/10 ignition control unit from the right engine compartment fuse box, the car no longer start, not even cranck. The battery is charged, the remote control is working, the shift moves when the brake pedal is depressed, and the engine fans start running in the run position of the key.

Any ideas what to look for. Can I test the ECU(N3/10) with the DAS software?

Please reply. Thank you in advance.

Darrel

the anti theft and ignition are tied together,you will either need to fix or buy a control unit,or find schematics and hot wire ignition. Also my s class has a k38 relay under the fuse box,that also controls sarter.I don't know if this was carried on in the newer s class

Thank you. I will start with the K40. Also check on the anti-theft.

Darrel

Move the shifter to neutral, unlock, lock, and unlock.. Try that..

MArtin

I tried to get the codes, there are many faults but there is no communication with the ECU. The message says: communication Error: communication with control module interrupted, possible causes...
But I just notice the battery was very low on voltage, 9.3V as per DAS, and 9.95V as per Fluke multimeter.

That may be the cause of all my problems, I will get the appropriate voltage and go on with the test.

Is it possible go get this kind of problem with a low voltage?

Thanks!

Darrel

A bad battery is enough to do it. Replace that battery.

I just charge the battery, it went up from 9.95V to 12.48V as per the Fluke meter and 13.1V as per DAS. Again same message, "communication error with the control unit". It seems like N3/10 is fried. I also tested the battery with my Snap-on instrument, and it tested good at 12.48V and 698 CCA AFTER Charging. Can I open the ECU to inspect it visually? Any thoughts are welcome.

Darrel

This is the message I get on the screen. Now that the fan is running voltage gets low. See the attachment. ECU PART NUMBER IS A0305455932, Bosch 261 206 971. Darrel

Try swapping the kH starter relay (MB p/n 002 542 23 19) with a known good relay and see if that helps.