08 GEN 4 No spark

[SketchyPete]

Hi all, new to the viper game aftering having made a sketchy transaction. Ignoring all that, the car has an incorrect battery hooked it and that is also on a charger.

Fuel was bad, disconnected line and drained it. Added fresh gas. Since it's a return style system, what was left should be diluted enough with good gas to not be a problem.

Key fob was dead, replaced battery. Door/unlock buttons now work. Held down both lock and unlock for 10-15 secs, no reaction from car.

I did notice when we plugged it up, that a red light flashed a few time under the rear view mirror, but I didn't think to much of it or count flashes.

Pulled plugs, they look good but do smell of old gas.

Pulled spark boots on 2 banks left and right, no spark.

When attempting to start, the key will cycle on, fuel pump cuts on and engine turns over for perhaps 3 secs or so and then stops trying to crank. Must recycle key to attempt another start.

I did the positive to negative battery connection discharge. No change.

I think there is some type of an anti-theft system that has the ignition shut down.

It could be the crankshaft or cam shaft position sensor. Ideas on testing those would be a big help.

If anyone knows how to reset the security system, I don't think I did that right or it's not working since no headlight flash response to the both fob buttons held down test. My the key has to be out of ignition or doors locked?

Any other suggestions would be helpful. Thanks for the help and support in advance!

 

[Steve-Indy]

Call me. 317 402 9013

 

[proedge]

Not sure if the security system is your issue. My friend had a similar thing happen on his Gen 4. He thought he unlocked it, went to start it and the car fired up and then immediately died. On the next key cycles, it would not even crank. I told him to close all the doors/trunk/hood, lock the car from the fob and unlock it, then try start it. The car fired right up and stayed running.
My point is, if the anti-theft was engaged, your car would not crank at all.

 

[SketchyPete]

Big props to Steve for a personal phone call and tech sheets. What an asset to have on a forum, amazing!

Mystery continues as follows:

Cmp control dark brown / white
Ks2 white brown
Ks1 blue light green (so far as I can tell)
Ks2 dark blue yellow

These are the wires on the c3 connector that have electrical tape on them. Also I found a fuse or relay box of some sort with the cover off and what appears to be a relay missing.

If anyone could tell me that that box is and if there should be a relay there that would helpful

 

[SketchyPete]

I think Steve and proedge are correct that is not security related.

I need to make a friend with good scan tool.

 

[proedge]

Big props to Steve for a personal phone call and tech sheets. What an asset to have on a forum, amazing!

Mystery continues as follows:

Cmp control dark brown / white
Ks2 white brown
Ks1 blue light green (so far as I can tell)
Ks2 dark blue yellow

These are the wires on the c3 connector that have electrical tape on them. Also I found a fuse or relay box of some sort with the cover off and what appears to be a relay missing.

If anyone could tell me that that box is and if there should be a relay there that would helpful

That PCM looks like a used unit that came out of a junk yard or eBay. the "08 Viper" writing on it gives it away. Your issue might be that the VIN number on the PCM doesn't match the car. Like you said, you need a good scan tool

 

[SketchyPete]

Yes that's what we were thinking, it's clearly been removed.

Any idea about the relay box on the front passenger side?

 

[SketchyPete]

I also wonder if it would crank but not spark with an uncoded pcm

 

[SketchyPete]

I found this YT video. Might be on to something. Apparently there was an old school method of swapping pins to use a different ecu, that doesn't work on something like this

How to program VIN after ECU swap.

In this video I show you how to program a vin in the Toyota after ecu swap if you need to program the immo security information watch my other video on how y...

youtu.be

 

[proedge]

I'm not sure what those relays are on the Gen 4, they aren't there on a Gen 3. The only relay that could cause a no-spark issue is the ASD relay. Find it, it might be in the main fuse box. Try swapping it with another relay and see if that works.

 

[SketchyPete]

Swapped asd relay with headlight relay, no dice

 

[TexasViper35]

Turn the key to On and then to Off 3 times, stop in the On position on the 3rd turn, a code or codes may appear where the odometer is located. Install a correct battery.

Many times people throw new parts at a problem that they can’t figure out, that may be why you have replacement eBay items on the car. They may have installed a replacement CPS sensor too, you should look to see. Everything you are doing now was likely done by the previous owner and they gave up. You can save yourself a lot of time and money by towing the car to a dealership with a Viper Tech; it will probably cost $175 to diagnose but that charge is waived if you have them do the repair(s).

 

[SketchyPete]

Funny I just called the dealer and they told me $149 to have it diagnosed, sounds like a plan

 

[latamud]

If it had old fuel in the lines it might also have clogged injectors. I often have to pull mine and unclog after sitting for a long time.


If you haven't replaced the battery just do it. But a battery tender at the same time and keep it connected when not in use. Vipers want a FULL charged battery. On my 08 I even have a permanently connected solar charger mounted on the package tray in the trunk so it gets charged even wen I'm out.

If you haven't checked, my guess is crank or cam position sensor, its on passenger side of the block by the engine mount, check to make sure its plugged in. Also they're like $35 at AutoZone and is not a bad idea to have a spare in the garage if that isn't what is wrong. The crank and cam sensor on an 08 has 3 wires going to it. 5v, ground and signal.

The cam sensor is under the intake manifold towards the rear of the engine.

You could tap into the crank signal and even cam signal at the ECM plugs to see if there is a signal when the engine is turning over.

ASD relay, my experience when this engages, the car will not even turn over.

I know you're frustrated and are already looking into the dealership. Good luck and purse update us whatever you find.

 

[SketchyPete]

Thanks Latamud, would you happen to know what pin/wires and which connector the cam and crank signal come in? I wonder if that it was the taped wires are about?

I've tried to keep calm on this deal. I bought it knowing it was going to be a problem, so I'm getting what I paid for.

As I get older, Steve and others advice makes alot of sense to me. I've done the waste my time stuff before, with electronics this complicated it's seems like a no brainer if I can get a viper tech to tell me everything wrong with it for $150.

I've been looking into getting a Windows 7 laptop and setting up witech and drb3. I may do that eventually anyway just because, but for my sanity getting (hopefully) most of the way there the easy way sounds really nice.

I may go through all this to also learn that it needs a rebuild.

 

[Steve-Indy]

Cam position sensor (CMP) signal is pin 22 of C1 connector of PCM...DarkBlue/Brown wire.

Crankshaft position sensor (CKP) signal is pin 25 of C1 connector...Light Blue/Brown wire.

 

[SketchyPete]

Awesome thanks Steve.

That's interesting. The wires that have tape out of c3 black/neutral are as follows:

Cmp control dark brown / white
Ks2 white brown
Ks1 blue light green (so far as I can tell)
Ks2 dark blue yellow

Cmp seems cam related then, no idea what ks wires control.

 

[Steve-Indy]

Forgot to add that "ks" refers to. Knock Sensor 1 and 2

 

[SketchyPete]

Here's my update, with no update. It's too damned hot! I'm still around though if anyone comes up with mean time suggestions.

 

[my427cobra]

Hi SketchyPete. Been to the Viper tech yet?

Any resolution?

Cheers
Greg

 

[SketchyPete]

Hey Greg,

Not yet, bruises my pride a little haha! I've been doing pin out testing, and odds and ends. I have been told to crank the car with the fuel line off and if it pumps gas while cranking then the crank shaft sensor is good. I got another cam sensor the other day, I'll toss that on just to see.

I wanted to get it a certain level of respectability before I showed my face at a dealer. The AC compressor was locked up, changed that out, idler pulley was missing, replaced that, got a belt on it and few other things.

I'm posting the values I case anyone has an opinion. I found that with the ckp and cmp plugged in, the car cranks for about 3-4 cycles and then I have to reset the key to try again.

With the cmp unplugged, the car will crank and crank (as it should I believe). I tried the same with ckp unplugged and the limited start cycle continued.

So leaning towards cmp being a possibility, but doubt I'm that lucky. I personally think it's a bad PCM/bcm.

Thanks for checking in!

 

[SketchyPete]

Pin out back probe voltages, key on

 

[SketchyPete]

That PCM looks like a used unit that came out of a junk yard or eBay. the "08 Viper" writing on it gives it away. Your issue might be that the VIN number on the PCM doesn't match the car. Like you said, you need a good scan tool

I was able to use a cheapo scanner, the car said no communication to run tests. Obd2 codes are present and appear to be functional. Auto vin scan failed.

I was able to manually enter the vin. Now, auto vin scan pulls up the vin. (I probably should double check the correct vin was entered again in case I was tired or hallucinating)