Voyager 3.3L Engine Cranks but no start CMP CKP ASD PCM Suspect

[TinTent]

Hi Everyone,

I am hoping someone can help me with the next step in determining the cause of my Chrysler Voyager 3.3L petrol 2002 EGA engine.
At the moment the car cranks but does not start, not even a splutter. I will describe the process I have gone through so far in trying to solve this problem.

Initially the car would cut out suddenly like a switch then after the engine was left for about an hour or so it would start OK.
This has happened about 6 or 7 times and the last few were predictable. From a cold start engine would run for about 10 minutes then cut out.
Now it wont start at all. On the first few occasions it would throw up a P0340 - CMP sensor code.

So, I undertook the following in order and after each instance no change:-

1. Cleaned and remade earth connections to engine and under battery tray.
2. Replaced Camshaft Position Sensor (CMP)
3. Checked operation of ASD (Auto Shutdown Relay) and fuse
4. Replaced Crankshaft Position Sensor (CKP) [This was a problem as it dissintegrated and had to be drilled out]
5. Removed two 40 pin PCM connections and fuse and relay box connections to check wireloom continuity.

• CMP left pin to pin 33 PCM=0.1 ohm
• CMP centre pin to pin 11 PCM=0.3 ohm (Was 5 ohm but patched new wire to wiring loom)
• CMP right pin to pin 44 PCM=0.2 ohm
• CKP left pin to pin 32 PCM=0.1 ohm
• CKP centre pin to pin 11 PCM=0.1 ohm
• CKP right pin to pin 44 PCM=0.1 ohm
• Ignition Coil left pin to pin 3 PCM=0.2 ohm
• Ignition Coil centre pins are both the same and connected to Blue connector on Fuse Relay board pin 30 on ASD relay =0.2 ohm
• Ignition Coil right to pin 2 PCM=0.1 ohm

So this seemed to assure me that the CMP and CKP connections which the PCM uses to activate the ASD relay are fine.

I then removed the ASD Relay and placed a jumper wire between pins 30 and 87 which I believe will force supply to Ignition coil, injectors and fuel pump.
Still no start and all confirmed with no spark at spark plug.

Replaced Ignition coil with new. - Still no spark.

Immobiliser light is Off . Used both keys to try and start.

So with all of this I am now thinking it might be the PCM ECU. I had read that generally pre 2004 PCM's can be just swapped without re-programming.
So got a second user one without keys or transponder.
Fitted this but as perhaps expected the immobiliser light activates and will not clear.

So I have exhausted what I believe I can do on my own. I am reaching out to anyone who perhaps can spot someting I have missed or if my conclusions are OK, advice on what the next step might be would be appreciated.
For Example, Is it possible to test PCM. Can you swap Eproms? I probably think that sending the PCM away for testing or reprogramming is perhaps called for.

Looking forward to some advice from anyone with experience in this area.

Cheers...

[TinTent]

So,
I learned that the ignition coil has three coils after looking at the workshop manual. The connector has 4 pins. So I figured that there must be one supply and three control wires for this circuit. Two of them are tied to 12V on the fuse board, so something is not right I think. I disconnected the two 40 pin plugs to the PCM. I chose the black and white wire/Pin 2 on the ignition coil plug and it has about 0.1 ohm on pin 6 and about 11 ohms on each of pins,7,8,10,13,14,15. So I might be measuring the coils on relays.

My Workshop manual does not have wiring diagrams for the Ignition Coil or PCM and Fuse/relay board. I am going to search for these and continue to investigate.

[TinTent]

So I have learned a bit more.  I have found the pin outs for the two PCM Plugs. I have attached for future reference. The fuse relay  board has been removed and I am left with the wiring loom connector ends, PCM connector ends and have started to disconnect engine sensors and testing continuity from the PCM plugs to the individual plugs of engine sensors. I had originally suspected problems with the ignition coil connections. I have confirmed the following:

Ignition coil connector 1 to PIn3 PCM=Ign Coil 2 Driver.

Voyager Mk4 PCM Pin Connector PIn Outs.docx

[TinTent]

Accidentaly posted before I had finished....

Ignition coil Connector 2 to pin 11 PCM= Ign Coil 1 Driver
Ignition coil Connector 3 to pin 5 PCM= Speed Control On/Off Switch Sense
Ignition coil Connector 4 to pin 2 PCM= Ign Coil 3 Driver

So The three coil circuits all check out OK, but connector 3 seems to wander off.

This pin connects to PCM pin5, Speed control Connector pin 1, Battery Earth connector terminal and the Brown/White wire and Yellow/Grey Wire on the Blue connector on the fuse board. I think that this is not quite right. I suspect the wiring loom may be at fault. What would help me is a wiring diagram of the engine wiring loom or at least the pin outs for the connectors to the fuse relay board, paricularly the Blue connector (attached). I dont think the Brown/White and Yellow/Grey wires should be connected together unless they are earth wires for other sensors/relays. A wiring diagram would help me look in the appropriate place.

Any help or suggestions would be most welcome. It's cold up here and I can only last for an hour or so before I have to come back in for warmth. (:>)

Many Thanks.

[bignev]

I really wish I could suggest anything useful, but you're WAY ahead of me on the diagnosis!

But, no spark on any of the 6? Means the PCM I think. Or earths for the ignition system. I'm sure they've been checked, but as a guy on another forum keeps reminding - it's not always a complex answer.

From our Subaru, on the Outback forum, some guys have reflowed the solder by putting it into an oven for a few minutes!!!!! I am not an electronics expert AT ALL, but they claim it worked for them to cure a serious misfire situation.

I'll keep looking in with  the hope of updates, and if my brain does come up with owt I'll shout up!

Edited February 1, 2023 by bignev

[RichardM]

Sorry I don't think I can help at all.

The circuit diagram for the V8 in the workpoo manual is totally different to your description and image. There is no BLUE connector on the coil circuit,  there is no blue connector at all with a pink tab.

Coil Control No.1 - Pin 3 Ign Coil fed from pin 10 on the PCM K19 DB/DG                                Connector C2

                                Pin2                goes to Pin 3  on the IPM  K342 BR/WT (Auto Shut Down)   Connector C4 

Coil Control No.2 -Pin 4 Ign Coil fed from pin 9 on the PCM K17 DB/TN   Connector C2

Coil Control No 3 -Pin 1 Ign Coil fed from pin 7 on the PCM K18 BR/OR   Connector C2

 

How the hell did you upload that image - I cann't load the smallest image at all ! 

[TinTent]

So, I noted a difference of the Brown/White and Yellow/Grey pins on the blue connector. They both are grounded to earth. But, when I disconnect the downstream O2 sensor, The Brown/White connector is no longer earthed. So, I assumed a faulty O2 sensor. Got a new replacement, fitted and it is just the same.

[TinTent]

On 2/6/2023 at 7:12 PM, RichardM said:

Sorry I don't think I can help at all.

The circuit diagram for the V8 in the workpoo manual is totally different to your description and image. There is no BLUE connector on the coil circuit,  there is no blue connector at all with a pink tab.

Coil Control No.1 - Pin 3 Ign Coil fed from pin 10 on the PCM K19 DB/DG                                Connector C2

                                Pin2                goes to Pin 3  on the IPM  K342 BR/WT (Auto Shut Down)   Connector C4 

Coil Control No.2 -Pin 4 Ign Coil fed from pin 9 on the PCM K17 DB/TN   Connector C2

Coil Control No 3 -Pin 1 Ign Coil fed from pin 7 on the PCM K18 BR/OR   Connector C2

 

How the hell did you upload that image - I cann't load the smallest image at all ! 

I just dragged the image from desktop into the text field.

[RichardM]

Aha - isn't life amazing

[TinTent]

So Just an update....
Thanks to RichardM i was able to test the individual sensors and wiring with more detail on resistences etc. Now the most suspect item is the PCM - Power Train Control Module or ECU. I have learned that this is in harmony through the can bus with the immobiliser. So I am now in the area of trying to test or clone the ECU. The unit was sent to one well established company who could not test it. So, It is with another who do cloning by transferring the eprom chip to a doner ECU. That's the stage I am at at the moment, however upon dismantling the ecu, the main circuit board is covered in a jelly structure that is difficult to remove and see through. They dont know quite where this chip is so it is taking a bit of time. If anyone has had experience of cloning and where the chip is would be helpful. If this does not work I think I may have to get a whole set of ECU's and immobiliser and keys from a dismantler. It would appear that if this ECU was a bosch, they are relatively easy to clone and electronically disable the immobiliser.

Seems I am down a rabbit hole and may not get back out !!