g35 no spark

[Motohead1]

A little background on this car its a 06 g35 coup It was supercharged at one time but I got it after the charger had been yanked and car repo'ed.

I am trying to just get it back to stock.

Car turns over it has fuel pressure and the injectors are squirting as I have fuel getting on the spark plugs. New stock ngk 5 heat range plugs btw. I have no spark at any coil I looked at them all. I am getting 12volts at the coil harnesses with the key on.

I inspected the harness for splices from the charger kit and there were none so they must have used a in-line harness witch is long gone. I pulled the ecu and it has no stickers on it from for aftermarket burning. It also looks as though the ecu has never been pulled just the cover below it.

The ivis light is flashing normally as it should and it goes out when i turn the engine over. It dosent look like an alarm issew. I checked all fuses including under hood and drivers kick panel. Also the keyfob works fine. There is only one key for the car and its an orginal Infinity key. I did the key relearn 5 sec on 10 off X2. Is there a way to confirm the receiver is getting the correct signal from this key?

If I can just get this thing to spark I am sure it would fire up.

[fixer]

CK THE CONNECTIONS AT THE CAM SENSORS, back of both heads, and crank sensor at front of trans on bell housing, you may be getting spark but at the wrong time, computer needs to know when its top dead center. pull a coil out and install a loose plug to see if you actually have spark or not.

[longhornsqx4]

He said he already did check for spark on all the plugs and got nothing

My guess is fuse

[SteveTheTech]

Nah it's more likely than not a sensor failure. This is not an easy one to check without access to an oscilloscope. Anything else will be a basic shotgun guess as the cam and crank sensors are Hall Effect sensors and a loss of any of these sensors will cause a no spark no start condition. You may be able to narrow it down by retrieving any pending DTCs.

There could be any number of things that are causing this, the internet may not be able to fix this one.

[Motohead1]

Nah it's more likely than not a sensor failure. This is not an easy one to check without access to an oscilloscope. Anything else will be a basic shotgun guess as the cam and crank sensors are Hall Effect sensors and a loss of any of these sensors will cause a no spark no start condition. You may be able to narrow it down by retrieving any pending DTCs.

There could be any number of things that are causing this, the internet may not be able to fix this one.

Steve I have no DTCs. Wish I had a scope. But at this point I dont feel so bad to load the parts cannon and sling parts at it but not being a high fail item I think some cheap junk yard parts might work fine for TS. I can pull 2 cam sensors and crank sensor perty quick. Ill let yall know what I find. Thanks.

[Motohead1]

Guys I have the 04 PDF version that I downloaded of the FSM but caint seem to find a strait ECU pinout? I am norwing it down and its looking more like an ecu problem. Were can i find a harness pinout for the 06 ECU That list all the pins and there destinations?

[fixer]

if you have no dtc may be crank sig fuse blown, or ign sw not sending crank signal to ecm. if you ck cracnk signal and there is 12 volts at ecm while cranking, then the cracnk sensor is fine, if ther is no signal from crank sensor there will be a dtc.

[Motohead1]

Crank sensor is getting 12v and has a good ground. Im waiting on a scope to dive back into this sucker might be here monday.

[Motohead1]

Ok I got no signal from ecu pins 8,9,10,11 witch is the intake/exhaust timing control banks 1 and 2. Key on I have 12 v and turning it over it drops to 10ish when turning it over but there is no 7 to 12 v pulse on the scope like there should be. Also I confirmed there is 12v at the sensor plug and the ground pin is fine also.

Crank sensor pin 13 is good. gives a nice square wave in range when cranking.

Pins 14 and 33 camshaft position sensors are good with a good signal cranking.

All ecu powers and ground were checked good.

Any ideas? I think I am gonna make some ground jumpers and make sure there is no ground problems.

[SteveTheTech]

Sounds like some good work so far. It sucks that you didn't find the failed component. This does indeed rule out several crucial sensors.

As I'm rereading the thread looking for a clue. I've seen a few demodded Gs and all kinds of things are possible. Is there any chance it could be in Lockout? Is the security light on steady while cranking is attempted?

If you've still got access to a scope check out this test. Page EC-628 of the 2006 GCP ignition output signal will give you an idea of whether the ECM is using the signals you have verified are being processed.

The pages starting at 628 are great for this type of fact finding mission you are on. You may want to print out a list of parameters (located in the top of the ESM) and fill them in as you test them (of the 120+ pins on the ECM many of the signals are redundant and it can save you a bunch of time retesting them) this will help you while brainstorming where to go next.

GL

[Motohead1]

Its not in lockout as I took it to the dealer last week to get the key re-learned even though the light was working as it should in a non-locked out car. They resinked it anyway. the old guy there said somthing about them getting floaded easy but no other hints.

My main concern is why I am not getting a wave form signal from either of the 4 exhaust cam sensors(2 for variable timing and 2 for phase). The 2 intake cam sensors are fine. Its my understanding that the exhaust cam send the signal to the ecu to fire the coils. And by the way I printed the whole ecu pinout list and checked every pin. Everthing at the ecu harness checked fine save for the 6 coil triggers and the 4 exhaust cam sensors.

I have a 4channel scope now so its gonna get fixed.

[Motohead1]

Steve let me ask this. There was 2 volts on the can bus wires on the ecu with no key in the ignition . Is this normal? What info besides alarm stuff could be running on the bus with the car completly off?

[SteveTheTech]

I have a 4channel scope now so its gonna get fixed.

I've only got a communal 2 channel Bluetooth unit that works with our laptop. I have always wanting to buy one but cannot find the right one. Not getting payed to diagnose warranty concerns makes it hard to justify buying one atm thought. I'm green with envy though.

Steve let me ask this. There was 2 volts on the can bus wires on the ecu with no key in the ignition . Is this normal? What info besides alarm stuff could be running on the bus with the car completely off?

CAN wires transmit and receive many signals (see image below), they may be active until the control units time out and go to sleep (~28 minutes). Diagnosing LAN lines is not accurate since the coded information is broken down into digital packets in the microvolt range (0.0001). The diagram below shows the communications tree, there is a priority assigned depending on which control unit is sending which signal.



No exhaust cam signal? At the ECM or Sensors? Power supply and ground are good? If so, I would pull the sensors and check the signal plates. Did the car run before and just stop? Loosing one sensor is possible but if all of the exh sensors are out (seeing as how they share common ps&g with other key sensors) timing may be a concern. How does the engine turn over?

[Motohead1]

Man I just picked up an old OTC scope used for a few hundred. With all the moduals and leads its great. Hasent been updated since 97 but who cares I just want it for the scope/meter abilitys. Sucker was $3K when new. Check ebay and craigslist there out there cheap.

As for the ex-cam sensors. I checked everything at the ecu harnesss to confirm wiring and when I got no wave form on all 4 exhaust sensors I when under the hood to confirm and I got nothing from the sensors out there to. All have good power and grounds from the sensor plugs so I have 4 broke sensors or somthing is up with both exhaust cams or there is a weird ground issew. Ill get back to it monday.

[SteveTheTech]

Moto~ Sounds like a good score, equipment like that, if properly maintained and used correctly last a very long time. I have looked into that before but many fail to meet some basic needs I have for portability and the ability to display in a minimum of 40 μs and 500 mV to justify spending the money. Actually my current DMM is a used Snap On 75th Anniversary Edition that works great even after 10+ years, although it was rarely used until I bought it.

Ok back to work. Ok this is an example of one of your exh timing sensors (Please note that only the 6 speed has these sensors and the magnetic retarder setup). The BOLD wires are all detectable so if there is a variance in rationality under the known conditions a specific DTC will be stored. So if power is verified at F108 terminals 119,120 and F46 #3 you know the ECM relay and its related circuit are intact, I would shy away from testing the ECM grounding signal (F108 #111) with other than an isolated continuity verification (to prevent any possible damage to the internal diodes in the ECM). Many of the EC sensors are grounded through the the M30 and M66 common grounds located behind the glovebox and under the combination meter assembly. A compromise in one or both of those can cause a myriad of problems with the engine control functions. However; the first sign of that is an intermittent U1000 and various warning lights.

If you lived closer I'd grab a six pack and stop by to brainstorm this one with you, but unfortunately the only thing I can do is guess.

[Motohead1]

Steve I appreciate all the help so far. Youve been a big help. 2 peaple bouncing ideas is always better keeps me from second guessing myself.

Ok I went back over everything I have already check as it turned out I had the scope on 50us on a few checkes were it need to be lower. So after recheck here is what I know.

Pin 8 and 9 dosent matter as the ecu pulses this info to the Exhaust valve timing control magnet retarder after 1500 rpm. its an out put not a ecu input.

pin 10 and 11 also dosent matter that much as its the same as the above.

Pins 14, 33, 53, and 72 are the cam pos/phase sensors that give the ecu its timing input along with pin 13 crank pos sensor. They are all outputting a nice wave form as they should all the way to the ecu. SO the ecu is getting all the timing info it needs. Im ready to pull the trigger on a ecu. Its got to be fried in there somwhere.

[SteveTheTech]

True, there is no foldout section anymore and no direct pinout, of the 120 pins on there they are spread over many separate diagrams.

Quick side note, replacing the ECM at home is not going to yield you any results. Here's a quick excerpt from the Special Procedures under P0605.

2. REPLACE ECM1. Replace ECM.2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs.Refer to BL-268, "ECM Re-Communicating Function" .3. Perform EC-77, "VIN Registration" .4. Perform EC-78, "Exhaust Valve Timing Control Learning (M/T models)" .5. Perform EC-78, "Accelerator Pedal Released Position Learning" .6. Perform EC-79, "Throttle Valve Closed Position Learning" .7. Perform EC-79, "Idle Air Volume Learning" .

What's the back story on this car? Other than the SC what else was done, what happened just before it stopped running?

[Motohead1]

Yea I understand a non-virgin ecu needs the vin and key relearn. I will drag it up there again to the stealership.

All I know is it had a supercharger on it and it got yanked because the owner new it was getting repoed. As for why it dosent fire no idea. but if the imobilizer is not active and all the timing inputs are getting to the ecu it should be trying to light off the coils and its not.

I got a UM code ecu coming so we shall see in maby a week if thats the fix. I did a quick search and didnt see any ecu failure post. But there is a first for everything.

[SteveTheTech]

UM? U1000?

If the sob who got it repoed took the time to pull the sc it's highly likely they would have sabotaged something. It's juvenile butt you would surprised how frequently it happens.

I would be skeptical of other threads online with similar issues you are the proud owner of a problem car.

[Motohead1]

If you look on the ECU the number on it is UM followed by several other numbers. There was only one on car-part and it was cheap enough to give it a shot.

I just as you suspected sabotage and it still may be the case but I have torn this car apart and have unwrapped all wire looms including that related to the BCM and have found nothing. But the fact is the ecu is getting all the timing inputs it needs and its not even trying to fire the coils. I mesured at the ECU also and nothing. I checked the condensor and followed all the checks for trouble shooting related to the ignition so Im confident its all good there.
Modified by Motohead1 at 1:31 PM 4/7/2009

[SteveTheTech]

That sucks man, I feel for you. I've actually spent more hours than I care to admit to reading the EC section for this problem. I'm drawing a blank without getting into it.

There isn't much else to check into for the ignition circuit.

[Motohead1]

Well a new ecu didnt fix it. Im gonna start over today and make sure I didnt miss anything.

[Motohead1]

Ok crazy question. Is there logic built into the ecu that prevents spark signal if the cam and crank sensor signals where so far out of phase from each other? I ask cause I know this is true on a few high end imports. I confirmed mechanicle timing only on bank 1 I will comfirm both now.

[SteveTheTech]

Not as far as I know of, there is nothing I found in the ESM regarding this. If there were something like that I can only imagine it would work in conjunction with a hard DTC . However; if the ECM input signal from any of the sensors is faulty or flawed an ignition signal may not be sent.

If B1 is on time B2 should also be, theoretically. There are three chains on this motor and if the main is off your would know about it.

So I'm assuming you still have no spark?

[Motohead1]

Ok confirmed timing is perfect.

But I found somthing interesting. I pulled a coil out and ohmed it out. On all three pins in any combo it reads open! So I pop out the other 5 coils they read exacly the same. Open in any combo. Granted Im just using a normal meter but i should be able to get some resistive continuity through pins 1 and 3 amd I have nothing. Any COP coil I have ever seen should get somthing. Is it posible I have 6 fried coils? It would make sence and I hope thats the case.

Steve or anyone else can you mesure a know good coil with a standerd meter and see what you get? Im headed to the jyard in the morning but Id like to know ahead of time if im on the right track.

[SteveTheTech]

Here ya go it was a slow morning at work. This is a NIB coil. All readings are in MegaOhms.

1+31+22+3

[Motohead1]

Thanks Steve. I went to the house and got my good fluke and got the same readings. Crap this is getting anoying.

To top it off I did a little experiment and slide the #1 trigger wire pin 62 out of the harness at the ecu and with the key on taped it breifly to 12 volts and got a nice big spark.

So the fact still remains. The ecu is not sending its signal.

Ok is it possible the stealership is not flashing the vin completly? Just enough to make the imobilizer light work as advertized? is there a step they could be omitting? I highly doubt it but at this point Im grasping at straws.

[SteveTheTech]

For anyone else out there thinking of supplying 12V to any ECU output terminal, be advised that this is a very risky test and may damage the internal diodes in the ECM.

What you have done by jumping #62 is trigger the coil. This theoretically verifies the integrity of coil #1s power supply and ground circuits. Unfortunately that doesn't say much for the root cause.

Guess it's about time to go back to the basics.









This may be redundant, but over thinking some of these things is very easy to do.

PS Picasa is the best photo software I have used.

[SteveTheTech]

Crap I forgot a step.

10. CHECK ECM POWER SUPPLY CIRCUIT-V1. Disconnect ECM harness connector.2. Disconnect IPDM E/R harness connector E7.3. Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 18.Refer to Wiring Diagram.4. Also check harness for short to ground and short to power.OK or NGOK >> GO TO 18.NG >> GO TO 11.

[Motohead1]

I just went through all the above again. It all checks good.