I've got a 2006 Ford Focus with a 2 litre Duratec with a crank,no start problem. I have changed both crank and cam sensors and have power to all four coil over plug coils and to one side of the injectors on all with the key on but am not getting spark to spark plugs when cranking.I have power to fuse and changed relay to ignition. Could ignition switch cause this no spark, no injector pulse condition.
Tough problem. Obviously you know that for an engine to run it needs:
- Spark (at the right time)
- Four cycle engine functions (Intake, Compression, Combustion, Exhaust)
I'm assuming that this is your vehicle, it worked before, and now it doesn't. (i.e. the engine's four cycle functions are correct. Valves are present, the engine holds compression, the cam is timed correctly, etc... If this was a vehicle you bought in an inoperative state, you need to check all that stuff first.) Let's assume you correctly have identified no spark as your trouble...
And on a modern engine with fuel injection, we're fortunate enough to have an Engine Control Module, a computer, with feedback. You get codes for many faults... but here's the rub. Generally the faults are recorded affect only the fuel system. The system is not so helpful on troubleshooting electrical faults. There are a couple of exceptions.. you will get a fault for a coil on plug issue. If however the feed system to the coil on plug is awry, you won't know that.
You are going to need to obtain a wiring diagram for troubleshooting. Ford calls that document the Electrical Vacuum Troubleshooting Manual (EVTM). You are going to want to find the page for ignition. When you find that page, you will see that the spark signal originates inside the Powertrain Control Module (PCM).
- First you need to verify the wiring for the key signals from the PCM all the way to the coil on plug. You want to verify the wiring is intact.
- Next verify the hall effect signals from the crank and/ or camshaft. Its pretty easy to verify these. You can use a volt ohm meter and a screwdriver to test basic functionality on these sensors. I will say, they don't typically wear out.
- If you have a key / immobilizer issue the system will definitely set a code and a blinking light on the dash panel. No code indicates that is not what's stopping your car from starting up.
- Note that the spark "control signal" originates from inside the Powertrain Control Module. I believe your still uses IGBT (insulated gate bipolar transistors) for spark controls. And yeah, those chips (and/or the chip that feeds the IGBT) can go bad. That happens. And it doesn't set a code. And the rest of the PCM continues to function, creating messages for the bus, displaying mileage, etc. And this can be an ugly repair. Been there, done that. Read about it here...
If you do have a defective PCM, I believe Ford only sells those for a period of ten years after production. You should probably speak to the local Ford dealer service manager on this first (if you determine your PCM is kaput.) I had exceptional help with Autozone on an aftermarket PCM. These guys were awesome. The product was fairly priced. You send them your VIN number and mileage, they program the PCM and mail it back to your local store. You definitely want to do this at the local store, and not online. You will still have to have your keys programmed. My experience is to use a Ford Dealer for this. (see the details in the link above..)
Questions for you: Where are you located? Has this car seen a lot of hot temperatures? My guess is high temps lead to IGBT failure, if that is indeed the trouble...
Good luck with it. Let us know what you find.
Not sure we're on the same wavelength.
1) You will require the EVTM printout page showing the exact pins and wire colors for all inputs to the PCM. If you can't do this step, you aren't ready for the repair.
2) Let's first talk hall effect sensors.This is NOT a simple continuity test. Take sensor out of car, set on the bench. Hook up a VOM to ohms. Move the screwdriver near the sensor. Do you see a change in resistance while you are moving the screwdriver? (Y/N?) (Obviously this test is easiest on an analog volt-ohm meter). We're not looking for a resistance value.. We're looking for a change in resistance whenever a screwdriver is moved back and forth near the end of the sensor.
3) Next test the wires between the sensor and the engine computer. Leave your car keys in the house for these tests. Unplug the hardshell connector at the engine computer. You have two choices here. You can probe the sensor wire and ground wire at the PCM hardshell connector, with the screwdriver movement trick OR you can do continuity / short to ground / short to any other wire test. For the moving screwdriver method you will need to remove the sensor from its engine mount, so you have room to move the screwdriver. This will take two people, one to move the screwdriver and the other to read the VOM meter. Obviously for that second method, you will HAVE TO UNPLUG the hardshell connectors at the hall sensor and at the PCM module. Engine off. Obviously you will need a decent supply of extra wire and alligator clips to test both ends of the wire for continuity. Be careful with your probes so as not to bend or damage the individual wire connectors within the hardshell.
4) Have you checked the camshaft and harmonic balancer to ensure that the input to the hall effect sensor is present? Perhaps you've moved something when you made the previous repair on either input to the hall effect sensors?
5) Two other thoughts about the crank/cam sensors. According to this video the check engine light will go out while cranking if the PCM is getting cam/crank timing signals. (I have no knowledge of this, but it's possible...) . The other test is to look at the tachometer in the dashpanel, is it moving during cranking? If not, that would confirm a problem is timing signals. That's not a perfect test.. I suspect if the crank sensor is good you'd get rpm even if the camshaft sensor wasn't whole. I'm not sure of your exact setup.
Again, we're trying to verify that the camshaft AND crankshaft hall effect timing signals are adequately getting to the PCM for processing.
I'm assuming you've checked all relays and fuses in the vehicle already.
Note: One thought... I'm assuming that the Powertrain Computer Module(PCM) is solid and functional. Its not totally clear on the history of the vehicle. I'm assuming that the cam chain/belt alignment went south, and the vehicle was declared dead at that point. No way would a cam timing failure break a PCM. That doesn't make sense. On the other hand, it's totally possible that the vehicle sat in the back parking of some repair shop for a few years. And that's the rub. Its totally possible that the repair shop cannibalized that dead vehicle to keep other $$ customers on the road. If I was a repair shop, I'd certainly swap a PCM from similar make/model to keep a paying customer on the road. I don't really understand where this car came from. So it's possible that the PCM is also kaput. One thing.. if there was a PCM swap, you would definitely see a code for key inop. No code tends to suggest to me that PCM is probably the original.
And you haven't answered my question about vehicle location. WHERE ARE YOU LOCATED? HAS THIS VEHICLE SEEN HOT TEMPERATURES?
Let us know what you find.