No Start, No Crank, No Codes

[Wingback73]

Hi all - hoping you can provide some diagnostic guidance. No expectation of an exact solution, just confirmation of where I should be looking based on my research.

Basic situation:
Randomly my 2004 Rubicon 5-speed manual will neither crank nor start. All lights come on in the normal run position and battery voltage is 12.4-12.6V. There is no audible click from the start solenoid. There are no codes through the ignition/odometer method - simply reads dOne.

I would appreciate potential root cause confirmation/additions to the below:
1. Clutch position sensor - replaced fuse 20 with a 20A fuse to bypass the clutch position sensor. No change in behaviour. Presume clutch interlock is functioning
2. Starter/Starter Solenoid - tested starter for power and solenoid for power during crank. 12V present at starter, but no 12V present to solenoid during crank. Presume starter and starter solenoid are functioning
3. Bad ASD - appears I need to confirm that pin 3 from PCM is providing ground to 86 on ASD?
4. Crank position sensor?
5. PCM?

Again, this is intermittent. My daughter got stranded at school, the vehicle sat for 2 additional days/multiple starting attempts, but then immediately started when I was present to diagnose the issue. Similarly, when I went to move the vehicle in my driveway, it was dead for multiple attempted starts. I replaced the fuse in Step 2 and it started right up. I moved the vehicle 25', turned it off, and was unable to restart it (with the fuse still in slot 20).

I would welcome any additional suggestions for places to look, especially if it turns out that the PCM is not providing the required ground to the ASD. I understand that O2 sensor wires are a common culprit...

Thanks!

 

[JKP]

On my 2006 Rubicon, you put the tcase in 4L to bypass the clutch safety switch. I don't know if this applies to your 2004, but very easy to test.

Did yours crank without pushing the clutch with the fuse in place?

 

[macleanflood]

You can probably turn the key to the run position and run a jumper from the big wire to the little wire to get it started.

The resources section has the factory service manuals and there's a troubleshooting procedure for the ASD circuit.

Might be time to check and clean grounds...firewall, battery terminals, two under each speaker cover and one on the driver's kick panel.

And then that same FSM has the wiring diagrams and you can continuity and ohm check wires.

Might also want to pull the connectors off the PCM and check for corrosion.

-Mac

 

[JKP]

Also verify the ignition actuator pin is not broken.

 

[Wingback73]

On my 2006 Rubicon, you put the tcase in 4L to bypass the clutch safety switch. I don't know if this applies to your 2004, but very easy to test.

Did yours crank without pushing the clutch with the fuse in place?

Ahh, good point, forgot about the 4L. I'll check that. I still pushed the clutch in (habit) figuring it wouldn't matter if bypassed. I will check this when I get home. Thank you for the reminder!

 

[Wingback73]

Thanks all! I'll check the FSM. I know I can jump it with a big wire, but need a permanent diagnosis since I can't have my daughter getting randomly stranded.

Actuator pin is a good call - I forgot about that.

 

[Wingback73]

Okay, so I could really use some additional help. Here is what I learned today:

1 - There are no codes in the system, confirmed through a diagnostic, not just the odometer
2 - The ASD relay is just fine - The relay itself tested fine and I tried a new one as well. Both tested fine and the vehicle sporadicially starts regardless of which is in there.
3 - Ignition cylinder seems to be fine - The key is just fine, or at least I see nothing physically wrong when I remove the cylinder
4 - Clutch sensor is good / irrelevant - I have the clutch bypass in place. It cranks, in gear, regardless of 4H or 4L. Not what I expected. Learned this the hard way when I accidentally turned the key to Start instead of Run
5 - Starter solenoid is good - Jumping the starter solenoid turns over the starter
6 - All major grounds are good - I have previously installed a Big 7 upgrade kit. All of them tested 0 resistance today

Additional diagnostic details:
I have 2 Jeeps: a 2006 and a 2004. Both Rubicon 4.0 manuals. The vehicle in question is the 2004 5-speed. When I remove the ASD from the 2006 (a 6-speed, although I doubt that matters) I do NOT get the same results as when I do the same on the 2004. I guess this could be intentional, but feels odd.

2006 - THIS VEHICLE RUNS FINE
30 - 12 V constant
87 - Ground
87A - Open
86 - ~37Kohm during Run / ~78 KOhm during Start
85 - Open during Run / 12.6V during Start

85 and 86 are, of course, the controls to actually trigger the relay to close. These values make some sense to me since they both go to the PCM (from what I can tell in the FSM)

2004 - the one with issue
30 - 12V constant
87 - Ground
87A - Open
86 - Ground
85 - 385 Ohm during Run / 12.6V during Start

It may be that this is normal given the change in transmission between the 2 model years but feels like it could also suggest a PCM issue.

These values are, of course, when the 2004 is not exhibiting symptoms. When it does have symptoms the 85 never goes to 12.6V, of course.

Using an ECT3000 I traced the 86 pin to the engine block. In other words, one side of the ASD trigger, which the FSM says is controlled by the PCM, is actually direct to Ground (through the engine). There is nothing wrong with this in practice, just doesn't match what I would have expected given how the 2006 works. I may have missed it, but I see no difference in the FSMs for the 2 years.

I'm all ears, and would very much appreciate any diagnostic suggestions. What I can't square away is the lack of codes. I would think that a PCM sense error of any sort would trigger a code, but there is nothing.

 

[CharlesHS]

With the starter relay removed from the PDC; measure the actuating coil ohms.
Should be around 70-75 ohms.
If too much resistance the coil may or may not create enough magnetism to pull in the relay consistently.
Replace if necessary.

 

[Painfultruth]

Okay, so I could really use some additional help. Here is what I learned today:

1 - There are no codes in the system, confirmed through a diagnostic, not just the odometer
2 - The ASD relay is just fine - The relay itself tested fine and I tried a new one as well. Both tested fine and the vehicle sporadicially starts regardless of which is in there.
3 - Ignition cylinder seems to be fine - The key is just fine, or at least I see nothing physically wrong when I remove the cylinder
4 - Clutch sensor is good / irrelevant - I have the clutch bypass in place. It cranks, in gear, regardless of 4H or 4L. Not what I expected. Learned this the hard way when I accidentally turned the key to Start instead of Run
5 - Starter solenoid is good - Jumping the starter solenoid turns over the starter
6 - All major grounds are good - I have previously installed a Big 7 upgrade kit. All of them tested 0 resistance today

Additional diagnostic details:
I have 2 Jeeps: a 2006 and a 2004. Both Rubicon 4.0 manuals. The vehicle in question is the 2004 5-speed. When I remove the ASD from the 2006 (a 6-speed, although I doubt that matters) I do NOT get the same results as when I do the same on the 2004. I guess this could be intentional, but feels odd.

2006 - THIS VEHICLE RUNS FINE
30 - 12 V constant
87 - Ground
87A - Open
86 - ~37Kohm during Run / ~78 KOhm during Start
85 - Open during Run / 12.6V during Start

85 and 86 are, of course, the controls to actually trigger the relay to close. These values make some sense to me since they both go to the PCM (from what I can tell in the FSM)

2004 - the one with issue
30 - 12V constant
87 - Ground
87A - Open
86 - Ground
85 - 385 Ohm during Run / 12.6V during Start

It may be that this is normal given the change in transmission between the 2 model years but feels like it could also suggest a PCM issue.

These values are, of course, when the 2004 is not exhibiting symptoms. When it does have symptoms the 85 never goes to 12.6V, of course.

Using an ECT3000 I traced the 86 pin to the engine block. In other words, one side of the ASD trigger, which the FSM says is controlled by the PCM, is actually direct to Ground (through the engine). There is nothing wrong with this in practice, just doesn't match what I would have expected given how the 2006 works. I may have missed it, but I see no difference in the FSMs for the 2 years.

I'm all ears, and would very much appreciate any diagnostic suggestions. What I can't square away is the lack of codes. I would think that a PCM sense error of any sort would trigger a code, but there is nothing.

The 2006 has a NGC controller and I would expect the 04 to have a JTEC, the ASD circuits are different.

The ASD/fuel pump relays are remaining engaged when the engine is cranking?

 

[Wingback73]

Thank you all! This has been very helpful, as always!

After some additional under his diagnosis I determined the starter relay is not receiving any power on crank (intermittently).

So I did what I probably should have done to begin with and went back to the beginning. Is turning the key generating 12V to the starter? Sometimes yes, sometimes no.

Ignition actuator gets replaced tomorrow. I'll be surprised if it isn't broken, but it's getting replaced one way or the other along with the switch

 

[Jepiep94559]

Thank you all! This has been very helpful, as always!

After some additional under his diagnosis I determined the starter relay is not receiving any power on crank (intermittently).

So I did what I probably should have done to begin with and went back to the beginning. Is turning the key generating 12V to the starter? Sometimes yes, sometimes no.

Ignition actuator gets replaced tomorrow. I'll be surprised if it isn't broken, but it's getting replaced one way or the other along with the switch

Did replacing the ignition actuator do the trick? I have an 06 LJ AT transmission with the same issue.

 

[Wingback73]

Did replacing the ignition actuator do the trick? I have an 06 LJ AT transmission with the same issue.

Sure did. 30 minutes later we pulled out the actuator/switch combo. My daughter said 'Doesn't look broken to me'. I separated the two pieces, a broken actually pin fell on the floor, and she actually cheered because we had a you cause.

Replaced both parts and running great.

To be clear, the symptom here is no codes (car doesn't know it is being started, so nothing to fault) and no or intermittent crank.

5 minute check - take off the steering column shroud. Check the yellow wire in the ignition switch for 12V when the car doesn't start. If you have 12V, look elsewhere. If you don't, change the actuator and/or switch.

 

[Jepiep94559]

Sure did. 30 minutes later we pulled out the actuator/switch combo. My daughter said 'Doesn't look broken to me'. I separated the two pieces, a broken actually pin fell on the floor, and she actually cheered because we had a you cause.

Replaced both parts and running great.

To be clear, the symptom here is no codes (car doesn't know it is being started, so nothing to fault) and no or intermittent crank.

5 minute check - take off the steering column shroud. Check the yellow wire in the ignition switch for 12V when the car doesn't start. If you have 12V, look elsewhere. If you don't, change the actuator and/or switch.

Great! I'm going to try this test. I'll let you know what I find. Thank you!

 

[Jepiep94559]

Sure did. 30 minutes later we pulled out the actuator/switch combo. My daughter said 'Doesn't look broken to me'. I separated the two pieces, a broken actually pin fell on the floor, and she actually cheered because we had a you cause.

Replaced both parts and running great.

To be clear, the symptom here is no codes (car doesn't know it is being started, so nothing to fault) and no or intermittent crank.

5 minute check - take off the steering column shroud. Check the yellow wire in the ignition switch for 12V when the car doesn't start. If you have 12V, look elsewhere. If you don't, change the actuator and/or switch.

I replaced the ignition actuator and the engine is now cranking over, but it's not firing on. Some progress as I now get the engine turning over. Still need to figure out why it's not firing to start.

 

[JKP]

If the crank sensor is bad, an 06 will start using the cam sensor, but it will be a long crank.

Check fuses, swap ASD relay with horn, can you hear fuel pump turn on?

 

[aston4]

On my 2006 Rubicon, you put the tcase in 4L to bypass the clutch safety switch. I don't know if this applies to your 2004, but very easy to test.

Did yours crank without pushing the clutch with the fuse in place?

What interesting info! I'll have to try this tomorrow see if my 97 works that way too.

 

[JKP]

It does not. It's a Rubi only feature.

Yours should have an offload fuse slot that you can put the spare fuse in to override the clutch switch.

 

[Jepiep94559]

If the crank sensor is bad, an 06 will start using the cam sensor, but it will be a long crank.

Check fuses, swap ASD relay with horn, can you hear fuel pump turn on?

So I swapped the ASD relay and now the engine turns over and it starts up, but it shuts down seconds later... Giving it more gas doesn't help once it starts shutting down. Not sure what it could be now.

 

[JKP]

Is your key gray? If so, it could be the SKIM system.

 

[RedTJinArkansas]

Any update. Your issue is similar. I'm going to go back through the posts and the diagrams now. I have a very similar issue with my 97, 4.0, 5 speed manual.

Starter won't turn over when ignition is turned to start. Resistance on the starter relay (pins 85 and 86) checks good with 78 ohms. I have 12 volts on pin 30 on the relay. I have 12 volts on pin 85 when ignition is turned to start. The clutch safety switch has been jumpered. I can jump the terminals on the starter solenoid with a screwdriver and the Jeep will start and run fine. Looking on manual page 8w-21-4. It appears the powertrain control module controls the ground through s134. I'm thinking the computer does not want to let it start. I had forgotten about the ASD relay but still thinking it's just that the PCM isn't happy and isn't going to ground the starter relay when it shold to start.