02 Liberty (3.7L) won't start. No power to fuel pump or spark...

[Michaelmcgo]

My Liberty died last week while driving down the road. I tried two OBD scanners but they both can't connect. I replaced the fuel pump/filter and the crankshaft position sensor. If I jump the fuel pump relay (which I know is good), the fuel pump turns on. It will not turn on when cranking. I also am not getting spark.

My theory is the ECM (computer) is burnt out. Does this sound right? Anything else I should try to fix first?

 

[sota]

find the ASD relay first and replace it or swap it with a known good relay.
ASD stands for Auto Shut Down. it basically kills all the power to critical things like fuel pump and spark.

you can bypass it also but I'd recommend swapping it first.

 

[Michaelmcgo]

I swapped with the working blower relay and also jumpered it (30 and 87). If this "kills" when on, would I have to jump the NC circuit insured?

 

[tjkj2002]

The ASD relay is the grounding circuit for all major systems like fuel pump,coils,and injectors.

 

[Jax2A]

The ASD relay is the grounding circuit for all major systems like fuel pump,coils,and injectors.

Do you know if the wipers are on the ASD relay by chance?

I'm chasing the same problem but my front wipers don't turn on either. Squirter works though.

No OBD coms.
No wipers.
No fuel pressure.
Fuel light on, but 1/2 tank
Fuel gauge doesn't go up at all.
Check engine light on.

Thanks,

 

[Jax2A]

Do you know if the wipers are on the ASD relay by chance?

I'm chasing the same problem but my front wipers don't turn on either. Squirter works though.

No OBD coms.
No wipers.
No fuel pressure.
Fuel light on, but 1/2 tank
Fuel gauge doesn't go up at all.
Check engine light on.

Thanks,

Last night I jumpered my fuel pump relay and fuel pump does run. I couldn't get the wipers to go this way but I didn't mess with the high/low relay, so I'm guessing I missed something there. I also swapped the ASD relay with the blower motor relay and confirmed the relay is good.

I did find this white wire with a worn spot and a couple of strands broke. This plug was mounted on the fender behind the battery. I was running out of light last night so I'll be repairing that next. Any one know what the wire goes to?

 

[rockymountain]

Last night I jumpered my fuel pump relay and fuel pump does run. I couldn't get the wipers to go this way but I didn't mess with the high/low relay, so I'm guessing I missed something there. I also swapped the ASD relay with the blower motor relay and confirmed the relay is good.

I did find this white wire with a worn spot and a couple of strands broke. This plug was mounted on the fender behind the battery. I was running out of light last night so I'll be repairing that next. Any one know what the wire goes to?

Battery temp sensor?

 

[Jax2A]

Battery temp sensor?

Hmmm... interesting. A couple/few broken strands could increase resistance (which I'm guessing what the sensor measures) which could screw up the reading... I've also heard when the batt temp sensor goes bad that it causes strange electrical problems. Will have to check that out too.

 

[Billwill]

Hmmm... interesting. A couple/few broken strands could increase resistance (which I'm guessing what the sensor measures) which could screw up the reading... I've also heard when the batt temp sensor goes bad that it causes strange electrical problems. Will have to check that out too.

I don't believe that is the battery temp sensor....but I have a CRD so I could be wrong. Battery temp sensor is two wires only...I will look up the colors of the wires for you sometime.
This is not important....firstly if there was a problem with the temp sensor then the red battery light would show up on the cluster...the same light as when you have a charging problem.
Secondly the battery temp sensor is there purely to slightly adjust the rate of charge from the alternator to the battery depending on the temperature....it is not a big deal and has nothing to do with your problem and does not cause weird electrical problems.

Can you tell me exactly what color wires are shown in your picture ie. White with Red stripe etc.?

You need to find out why you have the check engine light on...you need to beg steal or borrow a scanner to see what your Jeep is actually complaining about and your problem with the wipers is probably something totally unrelated.

 

[Billwill]

I swapped with the working blower relay and also jumpered it (30 and 87). If this "kills" when on, would I have to jump the NC circuit insured?

The NC side is not used.
have you changed the cam sensor?

 

[Jax2A]

Can you tell me exactly what color wires are shown in your picture ie. White with Red stripe etc.?

You need to find out why you have the check engine light on...you need to beg steal or borrow a scanner to see what your Jeep is actually complaining about and your problem with the wipers is probably something totally unrelated.

I'll have to look those wires again to be sure, I can't tell all the colors/stripes from the picture I took.

I have a scanner. The problem is that the OBDII port will power up my scanner but the Jeep won't communicate any data. A friend is supposed to be lending me his laptop cord so I can try it with another program though.

 

[Mindykimes]

Hi there I'm new on here ! I please need your help . It sounds like you all have the same problem I'm having ! My jeep is a 02 know power to fuel pump wire ! I replaced fuel pump! Fuel filter! All the relays and fuses! I ran a wire from fuses box to fuel pump it works now but still won't start!! Please can you help me

 

[Michaelmcgo]

Hi there I'm new on here ! I please need your help . It sounds like you all have the same problem I'm having ! My jeep is a 02 know power to fuel pump wire ! I replaced fuel pump! Fuel filter! All the relays and fuses! I ran a wire from fuses box to fuel pump it works now but still won't start!! Please can you help me

For mine it ended up being a wire in the harness had randomly broken. I towed it to the dealer and they had it figured out in a day with their fancy computer. I recommend you do the same. My repair was $300 and so worth it.

 

[rjkj2005]

Find the ASD (auto shut down) relay

You must be registered for see images attach

Sent from my SM-G900V using Tapatalk

 

[Billwill]

Hi there I'm new on here ! I please need your help . It sounds like you all have the same problem I'm having ! My jeep is a 02 know power to fuel pump wire ! I replaced fuel pump! Fuel filter! All the relays and fuses! I ran a wire from fuses box to fuel pump it works now but still won't start!! Please can you help me

Does the engine turn over but not fire?

Do you have the SKIS Amber "Key" symbol come on when you turn the ignition ON...this should happen if SKIS is installed but the light must then go out after a few seconds...not Flash or stay ON!

Do you get a spark?

Swap over the ASD relay with an identical one as shown by rjkj2005 and report back please.

If swapping over the ASD relay does not help, remove the ASD relay and find the female pins 30 and 87 inside the relay socket. Leave the relay out and briefly jumper these female pins 30 and 87 together inside the socket with a small section of wire, try start and see what happens when you turn the ignition to start...if it still does not start then remove the jumper and replace the ASD relay.:shrug:

 

[[email protected]]

I swapped with the working blower relay and also jumpered it (30 and 87). If this "kills" when on, would I have to jump the NC circuit insured?

Can you please help me I'm having same problem

 

[Killerer]

I am having the same issue I've replaced the cam and crank sensor I have a 02 liberty with the 3.5 I have no voltage to the coils even when cranking it did have a 20 am fuse that it blew the symptoms I was told about was the vehicle had all the gauges jumping around till you hit the breaks and the head lights would dim so the guy put a new alternator on it had it running then the battery started smoking so he pulled the positive off went to go put it in gear and the engine stoped now it has no voltage going to the coils and the fuel pump won't cycle the new parts on vehicle are cam and crank sensors altinator radiator and fan it's a nice vehicle just getting aggravated and never worked on one pz gelp