Have an ECU problem that has caused engine not to fire. Any suggestions?

If your Mercedes C200 W202 is not firing on two cylinders, and you've already changed the coil packs, plugs, fuel pump, and filter, here are a few other things you can check:

1. Check the fuel injectors: It's possible that the fuel injectors on cylinders 2 and 3 are clogged or not functioning properly. You can check this by swapping the injectors with ones from another cylinder and seeing if the problem moves with the injectors.
2. Check the wiring harness: The wiring harness that connects the fuel injectors to the engine control unit (ECU) may be damaged or have a loose connection. Check the wiring harness for any signs of damage or corrosion, and ensure that all connections are tight.
3. Check the ECU: The engine control unit (ECU) may be malfunctioning and causing the issue. A diagnostic scan tool can be used to check for any error codes related to the ECU.
4. Check the compression: Low compression in cylinders 2 and 3 can cause issues with firing. A compression test can be performed to check the compression levels in all cylinders.

If you're still experiencing issues after checking these items, it's best to have a professional mechanic diagnose and fix the issue. They will have the knowledge and equipment necessary to properly diagnose and repair the problem.

check fuel filter and fuel pressure

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no spark from coil directly?
is the cam turning, is the dizzy rotor spinning. ????

check all fuses first. Ig-coil, FI and dome.
then using diagnostic jumper wire or fuse, (as approp)
crank engine look for code 41 o 42.!!!

USA cars , answers only
our cars are all EFI that year.
no engine swaps to Suzuki G16A/B sidekick or tracker engines.!
1: engine cranks
2: no spark
3: The ECu makes spark
the CMP sensor in the DIzzy , (never fails if rotor turns, does rotor turn, if not cam belt igored and now snapped.)
the cam turns. the CMP fires. the ECU takes this CMP signal
and fires the ignitor next to coil and the coil charges, and release and BAM spark.

that is it.
the ECU will tell you when the CMP dies or the Ignitor fails
why not ask it.
1: key on
2: diagnostic jumper in place (flashes 12s for ok)
3: crank engine,for 5sec, not 1 ,not 2.
3: release key not off.
4: see code 41, or 42, BINGO !@!!!!

Yes the ECU should not affect the systems different firing order. If you want the correct ECU go here to purchase one.

If the check engine light does NOT come on when cranking, at the times when it won't start, and the relays are clicking and buzzing, then your ECU is in need of repair. The engine will only start after the check engine light comes on and the ecu is what controls that. ECU is likely going bad, causing the delayed start problem typical of early 90's jeeps. Reasonably priced repair or replacement services for your jeep ECU are available on ebay.

If the check engine light does NOT come on when cranking, at the times when it won't start, and the relays are clicking and buzzing, then your ECU is in need of repair. The engine will only start after the check engine light comes on and the ecu is what controls that. ECU is likely going bad, causing the delayed start problem typical of early 90's jeeps. Reasonably priced repair or replacement services for your jeep ECU are available on ebay.

If the starter does not turn over the engine, the battery is probably flat.

If it does, and the engine does not fire, its either

• a spark problem. Most common fault is the spark coil system (distributor or coil pack) has failed.
• a fuel problem. Check that fuel is reaching the engine.
• a fuel pump relay problem. This is behind the dash, and fail occasionally.
• an ECU problem. If the ECU is running there may be a Check Engine light on the dashboard. Read the ECU code for a diagnostic start suggestion.
• the ECU is dead (which happens) it has to be replaced with one from a wrecker.

yes

Hi I have a 1995 C200 Auto Sedan chs WDB 2020202F241703, I think I have a problem in the ECU. Only runs on two cylinders, I have changed the core pack on the 1 & 4 cylinders but the problem persists. The other problem is I don't know where the ECU (engine computer ?) is can anyone help ?

On 2.5L and 3.0L X-Types in the vin range C00294 to C91735 there was software issue on the engine ECU which caused misfires/hesitation when cold. this could be repaired by re-configuring the ECU with a software download. There was a Jaguar technical bulletin for this issue, the bulletin number was A303-05.