Hi,

I presently have an issue with my Honda Accord 2009 EX-L manual transmission. It doesn't start. When the ignition key is turned, the engine and kickstarter rolls, but the engine don't start, no combustion.

Let me take a little moment to detail and chronicle all events leading to this:

So, a week ago i started my car, and it couldn't move because the gear would engage when i depress the clutch. Obviously the clutch wasn't disengaging transmission. I called my auto mechanic who came and dismantled the transmission (gearbox) and the clutch. Discovered the clutch plate was in bad shape and he figured it was the reason why the clutch wasn't working. So he got a replacement clutch plate, coupled it and mounted the transmission (gearbox) back in place. Tried to start the car, but the engine won't start. An auto electrician was called, he checked all the fuses and wires and everything was ok. He then discovered power wasn't being delivered to the wires that feed the spark plugs. He then suspected a problem with the ECU (brainbox) - Engine Control Unit. He tried several diagnostic scanners (three advanced scanners) but the ECU couldn't connect to any of them. A replacement ECU was sourced and that could not also connect and be configured.

I am clueless and helpless now. Please someone in the universe should come and save me.

 

Did the auto-electrician look for parts of the wiring harness being disconnected? Did he know the clutch was just replaced?

I can only suspect that something was unplugged while moving the engine around & getting the transmission out. And forgot to plug back in. Or maybe the harness was pulled apart by moving the engine around.

 

Hi @JimBlake ,

Thanks for your response.

Yes, the auto electrician is aware the gearbox was dropped, clutch plate was replaced and coupled back together. All the events were narrated to him.

All the wiring and wiring harness have been checked, nothing seems out of place.

Is it possible the clutch system (wires, actuator) interfaces with the ECU or could interfere with the ECU?

I also have a GPS tracker installed in the car at the back, on the fuel pump line system which cuts off power supply to the fuel pump in the case of theft and stops the car. Could that cause an issue to ECU?

For now, it's established the ECM doesn't communicate fully with scanners and is not supplying power to the spark plugs but supplies power to everything else.

I really don't know what else to think or do.

 

There's no wires or actuator for the clutch. The only thing electrical is the switch at the clutch pedal to disengage the cruise control when you press the clutch pedal. So the only thing I can imagine is some part of the wiring didn't go back together the way it's supposed to.

No power to the coil-packs? Is there also no power to the fuel pump? Since you mention the GPS tracker that can disconnect power to the fuel pump, have you checked that out? Does it have a function/feature to disconnect that in the event a thief disconnects the battery? The battery should have been disconnected during the clutch replacement, so maybe that tracker has triggered its response to a "theft"?

If that's not it, I'm back to wiring not connected back up. Before getting into the tedious job of checking each circuit, I'd look for a couple things:
1. Getting the clutch out can become a brute-force job. Anywhere that you had to shake & pull on the engine/transmission assembly to separate them, look for parts of the wiring harness that may have gotten pinched. Either pinched by tools/prybars, or by the engine or transmission itself hitting the harness. A wire inside the harness might have been pinched, insulation broken, or cut altogether.
2. Check all the plugs again. This is less likely, but I've seen at least 2 times here on this board where a multi-wire plug was plugged back in, maybe not perfectly lined up, and one of the pins got pushed back out of the plug (instead of properly engaging its socket on the other side of the plug).

You say the ECM doesn't supply power to the spark plugs, but supplies power to everything else. The ECM doesn't supply power to the coils, but it supplies a signal to trigger them to fire. There's not a lot of "everything else" that gets powered by the ECM. Whats a couple examples of things you're talking about there?

The majority of items that are controlled by the ECM are actually supplied power directly from the fusebox via the ignition switch. The ECM controls those things by closing the ground side of the circuit. Solenoid valves for any number of things will have 1 wire that is hot (+12v) when measured against a ground. But you have to check whether the ground side of that circuit is open or closed before you can say the ECM is doing its job there.