Engine SHUT DOWN - ASD feed fuse blown

BrianUnderwood · **Posted:** Tue Aug 18, 2015 5:58 pm

Engine suddenly shut down when heading up a freeway transition ramp (from freeway to freeway) and had to be towed home. It threw codes; P0047, P0091, P0106, P0562, P0670, P1251, P2295...

I cleared codes, charged battery, and found a blown 15A fuse in the engine compartment (ASD feed). Replaced that fuse and now it's running fine.

Took it for a test drive and made it about a mile before the same fuse blew again.

I've read so far that it could be FCM, oil pressure sender, or some random shorted wire somewhere within the harness... I checked the harness and there seems to be no unusual wear behind the fuel head, or anywhere else I've checked. I'm feeling slightly proud, but still not out of the woods yet. Any ideas?

This is the most helpful thread; viewtopic.php?f=5&t=80457
but I still am unsure of how these dudes FIXED or tracked down the problem exactly, and I don't
want to start buying new parts willy-nilly...

Hexus · **Posted:** Tue Aug 18, 2015 6:19 pm

I make it a habit to change out my ASD relay, and it's brother, inside my engine compartment every 3 oil changes. Costs about $20, and since I've had an ASD relay cause a bad battery, and glow plug failure so far in my life, it's worth it.

Bushman5 · **Joined:** Sat Jul 11, 2015 11:05 am **Posts:** 278

someone have pics of the ASD relay (and what is it too?)

geordi · **Posted:** Tue Aug 18, 2015 11:55 pm

ASD is the Automatic Shut Down relay that kills power to the engine. It is a regular relay, nothing really special about it compared to other relays. But it has to be powered at all times or the engine will quit.

Brian, don't forget to mention that you have also had intermittent ABS lights?

BrianUnderwood · **Posted:** Wed Aug 19, 2015 12:43 am

Ah yes, almost forgot...

Over the last few months I've had 3 instances of the ABS light come on, then resolve within a couple minutes of driving.
But it has never caused a shut down before.

Can I buy an ASD relay at an autoparts store??? Or must I buy it from some horrible Mopar dealer?

geordi · **Posted:** Wed Aug 19, 2015 2:18 am

Luckily, a relay is a relay is a relay. You can get a 4-pin or 5-pin relay at any auto parts store, although you may need to convince the parts droid that they are all the same. Look through the power box and see what other relays are the same number of pins, and try swapping one of those in. The fan relays are popular choices.

I can't remember if the relay is a 4 or 5 pin, but the only difference is the circuit: 5 pin relays have a "normally closed" position, that opens when energized. Otherwise, they are precisely the same as any other relay. If the size matches, it will do the job.

Billwill · **Posted:** Wed Aug 19, 2015 4:14 am

Yep fuse 6 (30 A) feeds quite a few circuits....difficult to isolate the short.
Replace the ASD relay first...swap it out with an identical one nearby.

If that does not help you need to physically trace all the circuits...only the 2006 LHD CRD has the issue with wires behind the fuel filter head mounting bracket.

I know on my 2002 RHD Export 2.5 CRD the wiring from the Power Distribution center to the ECM and other components does not take a simple shortest distance rout but goes all around the engine bay like the Beltway in Washington DC!
When my SO hit the right front of the Jeep when a tree jumped in front of the Jeep I had plenty wiring problems after getting the Jeep back from the Autobody repair people...the main harness runs from the PDC, around the engine bay under the windscreen, goes through some connectors next to the air filter, runs under the radiator through a metal channel and then gets to the ECM up the LHS of the engine compartment...a distance of about 10 feet to connect two points 18 inches apart!

I had to find the shorts/semi-shorts by cutting off wires at all ends of the circuit in question and measure that circuit's resistance to ground with a meter to see if there was any conductivity...the circuit should have been floating in mid air after cutting the wires. When this was not the case I left the original wires disconnected and added a new run of my own wiring...taking the shortest route! I fixed about 6 problems like this, neatened up the new wiring and documented it on the relevant circuit diagrams which I then keep in the Glove Box for any unsuspecting future owner! :shock:

This was 7 years ago and so far no further problems. :wink:

You could try disconnecting all of the modules in the circuit...EGR solenoid, Boost Pressure solenoid etc. measure the resistance of the circuit to ground and re-connect the components one by one...maybe one of these solenoids etc. is shorted out!

BrianUnderwood · **Posted:** Wed Aug 19, 2015 8:10 pm

Well crap... Now the jeep will not blow the fuse no matter what I do, so I can't even diagnose it further!

geordi · **Posted:** Wed Aug 19, 2015 9:36 pm

Definitely sounds like a frayed harness somewhere. The problem is... It could be darn near anywhere. I'd just have some spare fuses with you and keep driving, and maybe it will present itself later. Upsizing the fuse one rating will help diagnose if it is just a heavier power user (for some reason like increased resistance in the ground) or if it is actually a dead short. A short will still kill the fuse, where a ground resistance issue usually won't. There is enough safety factor in the wires to put up with a couple more amps of fuse rating.

Billwill · **Posted:** Fri Aug 21, 2015 3:03 am

geordi wrote:

Definitely sounds like a frayed harness somewhere. The problem is... It could be darn near anywhere. I'd just have some spare fuses with you and keep driving, and maybe it will present itself later. Upsizing the fuse one rating will help diagnose if it is just a heavier power user (for some reason like increased resistance in the ground) or if it is actually a dead short. A short will still kill the fuse, where a ground resistance issue usually won't. There is enough safety factor in the wires to put up with a couple more amps of fuse rating.

Yep I agree with all this^^^

The fuse currently being used may have a slightly higher rating than the previously used fuses...the fuses are manufactured within a certain tolerance!

When I was in Support fixing Mainframe Computers etc. in the Field I used to carry some DC Circuit Breakers of various values with which I could replace a blowing fuse with while tracing down the problem....saves on fuses and these would have slight delay before tripping due to any surge.

We also used to get so-called "Slow Blow" fuses that would wait a few milliseconds before heating up enough to blow....some circuits cause a brief surge in current and then calm down to a lower steady value. I have not seen these Slow Blow fuses used in the Automotive field though!

geordi · **Posted:** Fri Aug 21, 2015 1:19 pm

I have, but not since my 83 Lincoln Town Car have I seen a car with them. They weren't used in the usual fuse box, I had a couple in some 12v accessories that I plugged in, and IIRC, there was one in the engine PDC that was for the AC clutch.

You had to buy them at Radio Shack b/c the auto stores didn't carry them.

jrsavoie · **Posted:** Fri Jun 10, 2016 5:03 pm

Any more info on the ASD Feed fuse and popular issues?

Mine blew yesterday and the new fuses blew as soon as I turned the key to on.

I didn't know the fuse went to a relay that could be changed so I never tried that. Now the Jeep is 20 miles away at a shop. Hope he gets it figured out in short order.

papaindigo · **Posted:** Sat Jun 11, 2016 8:35 am

There is nothing "special" about the CRD electrical system in the same sense and the engine is "special". Down here if one has a weird electrical problem one goes to a local auto electric shop, same place local mechanics and the dealer send weird electrical problems. They have the knowledge and tools to pretty quickly isolate problems.

jrsavoie · **Posted:** Mon Jun 13, 2016 7:54 pm

It sat for 3 days. Today the mechanic pulled the relay, re-installed it, added a new fuse and the Jepp ran for at least 8 miles and idled for 1 1/2 hours.

I picked it up and drove about 10 miles and had a rerun of the previous issue.

I waited for him to show up and removed the relay / swapped with a neighboring relay.

Nothing the fuse blows as soon as the key is turned to run.

Back on the trailer and back to the shop.

It showed no codes the first go round. He'll check codes again tomorrow.

geordi · **Posted:** Tue Jun 14, 2016 3:00 am

Jeff, the instant fuse blowing does suggest that you have a dead short that is being patched into the circuit somewhere, and the most likely source for my thought process is still the AC compressor.

Can anyone verify what else is on that fuse? I know it should be the computer, the ASD, and the clutch. What else is there?

Billwill · **Posted:** Tue Jun 14, 2016 8:09 am

jrsavoie wrote:

It sat for 3 days. Today the mechanic pulled the relay, re-installed it, added a new fuse and the Jepp ran for at least 8 miles and idled for 1 1/2 hours.

I picked it up and drove about 10 miles and had a rerun of the previous issue.

I waited for him to show up and removed the relay / swapped with a neighboring relay.

Nothing the fuse blows as soon as the key is turned to run.

Back on the trailer and back to the shop.

It showed no codes the first go round. He'll check codes again tomorrow.

You are lucky that the fuse blows as soon as you turn it to RUN...makes it easier to find the problem...lets hope it stays that way.

You have the 2006 CRD which has a known problem of the Fuel Filter Head Mounting Bracket having the wire harness going behind it and possibly damaging the wires there causing a short to chassis...if you have not checked the state of the wires behind the Filter Head Mounting bracket then I would suggest you do this first...can cause all sorts of weird problems and some of the ASD relay outputs do go through this area into the cabin. :wink:

Which fuse is blowing in the fuse box under the hood....fuse 6, 15, 16 or 26? Will help to narrow things down..although I can see some errors in the circuit diagram which is going to mess us around...not unusual to get these errors....I will have a look at the 2005 diagrams as well to see if they make more sense :shock:

Try pulling out...one at a time...the fuses I mention above and see if the blowing fuse still blows once the ignition is turned ON!

The ASD relay does energize the AC Relay as one of its many destinations but it is unlikely that the coil of a relay shorts out so as to blow a fuse...more likely a pinched wire going to one of the many destinations...pull the AC Relay out in any case!

Billwill · **Posted:** Tue Jun 14, 2016 9:01 am

geordi wrote:

Jeff, the instant fuse blowing does suggest that you have a dead short that is being patched into the circuit somewhere, and the most likely source for my thought process is still the AC compressor.

Can anyone verify what else is on that fuse? I know it should be the computer, the ASD, and the clutch. What else is there?

Juggling between the 2005/6 CRD Circuit Diagrams and depending on which fuse is blowing then other components on that line include: EGR Solenoid, EGR Air Flow Control, Boost Pressure Solenoid, Solenoid Vacuum Reservoir among other things.

Disconnecting these items one at a time could help...if the fuse stops blowing when ignition is turned ON after disconnecting one of these items would point to the problem but I am more inclined to suspect a wire chaffing to chassis somewhere!

jrsavoie · **Posted:** Tue Jun 14, 2016 9:08 am

The fuse that is blowing is labeled ASD feed on the cover. I am not sure which number it is assigned

papaindigo · **Posted:** Tue Jun 14, 2016 10:53 am

ASD feed is a 15amp fuse F-16. Go to http://colorado4wheel.com/manuals/Jeep/KJ/ and grab a PDF copy of the 06 FSM. Look at page 8W-10-12 for what runs off that fuse. Give that the vehicle ran fine for a bit when started cold but the fuse blew when things warmed up my, electrically uneducated, thoughts would would be something that kicks in and draws more power as things heat up which suggests the AC and/or electric fan just behind grill. My first suggestion is run with the AC fully OFF by either pulling the AC clutch relay (R-35) or switch the AC off in the cabin; NOTE if you do the latter the AC button needs to be off AND the vent position needs to be bi-level to prevent the compressor from cycling from time to time. If problem goes away the AC clutch is pulling too much power for the 15amp ASD fuse but not the 20amp AC clutch fuse. Go from there. I still thing a decent auto electric shop is your best bet.

Billwill · **Posted:** Wed Jun 15, 2016 9:24 am

@papaindigo...your logic is slightly wrong I believe.

I agree that page 8W-10-12 is a good place to start although it contradicts page 8W-30-2 which refers to fuse 15 (25 AMPS!)...not fuse 16..and has different color wires coming from the fuses....this is one of the errors I am refering to.

The point is that all the relays being energized such as the AC Clutch Relay have nothing to do with the current draw from the AC clutch itself..the AC clutch gets its power from another fuse...fuse 21...not fuse 16. Same goes for the Radiator Fan Relays for example..the fan itself will get its power from another fuse.

I am not saying that any of these relays may not be shorting out ie. when the PCM supplies ground to the other side of the relay it then draws too much current and blows fuse 16...this is possible although relays usually tend to burn out rather than short out. So all of these relays on this page of the circuit diagram can be pulled out, ignition turned ON...see if fuse 16 still blows.

Likewise the solenoids/valves I reffered to such as the EGR air flow valve, EGR exhaust circulation valve, Boost Pressure solenoid, Module Glow plug...all shown on this page 8W-10-12....need to be disconnected and once again with ignition ON see if fuse 16 blows....even the ECM Connector C3 can be pulled off. You could have a condition that one of these components is on the borderline of drawing too much current...when another solenoid or valve kicks in then the current drawn becomes too high and the fuse blows!

Fortunately from what I understand...the fuse blowing is immediate as soon as ignition is turned ON so all of these relays and solenoids can be disconnected. If all these components are disconnected and fuse is still blowing then I am afraid we have a wire chaffing to chassis somewhere! The OP needs to take these circuit diagrams to his Auto Electrician...if he does not already have them!

I would like the OP to check page 8W-10-2 which shows the layout and numbering of the fuses, relays etc. on the PDC so we are sure that we are indeed talking about Fuse #16!

Sorry, edited my post to reflect that the fuse layout is on page 8W-10-2! :oops:

Engine SHUT DOWN - ASD feed fuse blown

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