[priya9942]

A car cranking well but not starting is most likely caused by:
1. No spark: Have you pulled a plug wire and looked for a clean bright spark jump the gap to the plug or pull the wire and plug and look for a spark that way?
2. No gas: Have you sprayed starting fluid or even carb cleaner into the intake and see if it fires?
3. Timing: Is the timing belt/chain intact and is the crank/cam timing mark correct?

If you don't have the ability to check the above, you need a professional mechanic to diagnose your issue.

 

[priya9942]

The 4 codes P0351-P0354 are caused by the ECM not sensing IGF. This means that the ECM is asking for the 4 ignition coils to fire, but the coils aren't confirming that ignition actually took place by signalling the IGF wire.

There are 3 common wires (B+, GND, IGF) that go the 4 coils and 1 wire specific to each coil (IGT1 ... IGT4). Most likely one of the 3 common wires has a break somewhere or is shorted to ground. Since your fuse is fine, we know that B+ is not shorted to GND.

You'll need the wiring diagram for your car to know color codes for the 4 wires on each coil. Usually red/black is the thick B+ wire and brown is GND, but it does vary with each car.

Have someone crank the engine while you run the following tests:
Check for 12V on B on each coil by connecting the voltmeter to Battery negative and B+ on each coil.
Check for GND on each coil by connecting the voltmeter to Battery positive and GND on each coil.
Check for voltage fluctuations on IGF on each coil, Voltage should go between 0 and 4.5V.

Depending upon what you find, you should be able to trace that particular wire back to the harness and figure out where it is broken or shorted.

 

[priya9942]

He's throwing coil codes. That needs to be traced starting at the coil and working backwards to the ECM and if necessary further back to the Crank Sensor.

I would definitely like to get confirmation that B+, GND and IGF are connected and working at the coil before replacing anything. If they are all good, I'd look at the IGT1 ... IGT4 from the ECM.

It should take no more than 15 minutes to isolate this problem with a voltmeter.

 

[priya9942]

You need a backprobe kit to look at the electrical signals on the coil. Here's one I found on eBay: Item number 165045967719. Your local auto parts store may have one too but may be more expensive?

You connect 1 side of the voltmeter to battery -ve and the other side to the backprobe pin and insert the pin to each insulator on the 4 wires on each coil in sequence.

With the ignition ON and engine not cranking, you should see 12V at B+, GND at GND, 0V at IGT and 5V at IGF.

With the engine cranking, you should see voltage jump between 0 and 5V on IGT and IGF on each coil.

Anything different than the above means you can look at the wiring for that pin.

 

[priya9942]

A few notes:

1) B+ on the coil should not drop to 5V when cranking. Does it really drop from 12V to 5V? If so, you have to figure out what is loading B+ down so much. This is tough because so many things can cause this to happen ...
2) You have to first test with the ignition ON and no cranking. You should see 5V on IGF and 12V on B+ on all 4 connectors. Can you confirm that?
3) If everything (all B+, IGT and IGF) checks out at the coils and it still throws P0351-P0354, you have a wiring issue back to the ECM or (extremely unlikely) a bad ECM.

 

[priya9942]

Unlikely because it would throw P0335 for that sensor being out of range or circuit issue. He's throwing coil codes caused by failed IGF feedback to the ECM.

 

[priya9942]

My thoughts:
1) Charge the battery overnight with a low amperage trickle charger.
2) Confirm B+, GND and IGF at 5V on all 4 coils with the ignition ON and not cranking.
3) Confirm IGF fluctuating between 0 and 5V while cranking. This will provide some direction.
4) rpm measurement is an indication of crank position working. Nothing so far suggests any issue with the senor.

 

[priya9942]

1) The drop from 12V to 10V is completely normal.
2) CEL codes get erased when you disconnect the batter for a few minutes.
3) Bosch spark plugs are not right - you have to use Denso or NGK from my experience.
4) Can you confirm steady 5V at IGF when you are not cranking?

If IGF is good per above, I would next look at fuel. Spray some starting fluid or carb cleaner into the intake through the throttle body or EVAP port on the plenum and see if it fires. If it does, you are now down a completely different path of chasing fuel related issues such as injector connections, fuel pump, EFI or CirOpn Relays etc.

Please don't replace anything at this point as we progress down a step-by-step diagnosis. Any time you replace something, you have lost your baseline and have to start diagnostics again from scratch. Hope that makes sense!

 

[priya9942]

Fuel supply needs to be steady and with sufficient pressure and volume for the car to run. Smelling fuel on the spark plug doesn't say anything one way or other.

Yes, let's fully verify ignition before taking on anything else.

 

[priya9942]

Let's stay the course of confirming IGF to eliminate ignition from a possible cause. Next up: fuel delivery.

 

[priya9942]

The shared IGF should be 5V and each individual IGT should be 0V with the key in ON position and not cranking.

Both should fluctuate with the engine cranking. Your reading of 2V is normal though I would expect IGT to be lower than IGF. The multimeter reading can't react fast enough to show fluctuations accurately.

If the separate colored IGTs are at 5V on all 4 coils with the engine ON and not cranking, something is wrong. Are you sure about that?

I would unplug one coil connector at a time and see if that affects IGT. Something is pulling IGT up to 5V when it should not.

Please reconfirm and report back the above.

FYI: Attached is IGT and IGF on one of the coils on my 2003 V6. IGT mostly 0 and pulsing to 5V. IGF mostly 5V and pulsing to 0. In my case there are 6 IGF pulses for each IGT on any coil. Yours will have 4.

 

[priya9942]

That's why I was suggesting that he unplug one coil at a time to see if that fixes IGT.

Just need to reconfirm that IGT is locked up like that to 5V. Car won't run that way.

 

[priya9942]

I'm not aware of or familiar with any differences of this type between US and Japan cars. Others may be better equipped to address this question.

Your issue may be the ECM ground or something ECM or wiring related. As next step, I would check IGT1...IGT4 at the ECM pins by unplugging the connector at the ECM. I would expect to see 0V there.

If you see 6V on IGT1...IGT4 at the ECM with the connector unplugged, something is wrong with the ECM or ECM ground. You'll need a thorough check of power and ground at the ECM using your wiring diagram.

If unplugging the connector drops IGT1...IGT4 to 0V, your issue is the harness between the ECM and the engine bay or the ECM connector. You'll need to chase down the harness for breaks and grounds.

 

[priya9942]

Your analysis is right on point. It may be that the ECM is fine, just not grounded.

To address the question of how it happened and how to prevent recurrence, we have to first know exactly what happened. Did the harness, connector or some ground get damaged or is it loose?

Your on the path of narrowing it down already.

 

[priya9942]

Unplug the ECM connector that has the IGT1...IGT4 and check the voltage directly at the ECM pins. Goes without saying that you have to be very careful not to short out anything at the ECM pins. I use a shielded pin and wire so I am sure that it does not touch anything else.

1) If you still see 6V or 7V at IGT1...IGT4 and 5V at IGF with the ECM connector unplugged, your issue is likely the ECM.
2) If IGT1...IGT4 drop to 0V and IGF is 5V, your issue is the connector you just unplugged or the harness to which it is attached.

 

[priya9942]

Not sure if your issue was resolved?

 

[priya9942]

1. If your crank sensor broke and fell inside, it should be easy enough to pull the timing cover and take the broken part out. This has nothing to do with the oil pan. There should be zero oil at or near the timing belt. The belt has to be completely dry for the car to run right.

2. 7V at IGT has nothing to do with the crank sensor. Crank sensor is an input and IT is an output to/from the ECM. Your issue is a bad ground to the ECU or some harness issue.

 

[priya9942]

Forgot it's a 2003, so yes, it's a chain. Thanks for calling that out.

The sensor is attached to the timing chain cover on the 2.4 and if broken, should be laying at the bottom of the housing next to the crank pulley. How would it get into the oil pan?

 

[priya9942]

Is the oil inside the oil pan really exposed that way and if so, won't it slosh around and mess up the inside of the timing chain cover and dirt and debris from the timing chain tensioners also get mixed in with the oil? Forgive my ignorance, but I don't see how something can fall into the oil inside the oil pan.

 

[priya9942]

Found a good you tube video showing the oil pump chain and fully open oil pan:

Wonder if might be easier to drop the oil pan rather than the more complicated timing chain cover. The broken part should be sitting in the oil pan as you guys are saying.

Thanks for helping me understand this!