Hi,
Im new to the jeep garage hope im on the right section.
So yesterday I was driving back home on the freeway and all of a suden my car starts decelerating so I pull over to the side. Turn off the car and try to turn it back on and nothing. I got a buddy to come see what could be wrong and with his code checker he got the code "P1389" No ASD Relay Output Voltage At PCM.. This is the 1st time this has happend ever since ive had my car. The oil and temperature gage would not move there was no way of starting the car so it had to be towed back home. Any suggestion or help will be great I love my jeep its my daily driver.
99 Jeep Grand Cherokee Laredo
4.0 2wd V6
The help will be very appreciated.
Welcome to the garage. I would start changing the ASD relay in the Power Distribution Center (under the hood). There are probably some more same relays in there, so you could first swap it with an other one to see if that will solve your problem, before buying a new one. Also fuse 6 (30A) and 26 (15A) in the PDC could be the problem. And fuse 12 (10A) on the junction block (fuseblock under the steering wheel), check them out first. By the way, your engine is an I6.... Also the next time you would have engine problems, you can check the fault codes without scanner. Just switch the ignition switch 3 times from OFF to ON and leave it in ON after the third time. The odometer will show you your fault code(s), or DONE will appear when no faults present.
Frango 100 Thank You!
I dont know were the the ASD relay is located? So I started by changing the 12 (10a) fuse under the steering wheel. Turned it on nothing. So i went under the hood and found out that the 26 (15a) fuse was blown! so i changed it for another 15a and turned it on and it ran for about 30sec before it turned off and i checked the fuse and was blown again. did it once more ran for about a min and turned off again. but the oil gauge gauge rose but the temperature gauge did not move.
So there is too much current drawn, but not really a short circuit. Remove the negative battery lead and then disconnect the PCM connectors. Connect negative battery lead again and put new fuse on 26. Put the ignition switch in on and see after a minute or so if the fuse is blown again or not. If not, the problem is probably in the PCM. If yes, you probably have a shaved through wire from the PDC to the PCM. The ASD relay will not be the problem in this case, because the fuse 26 is after the relay in the electrical circuit.
Looking into the wiring schematic, i see that also all the fuel injectors are connected to this same fuse 26. So there could also be a problem with one of the injectors, or the wiring going to them. If the PCM seems to be ok, you could remove all the fuel injector connectors. If you have a multimeter you could measure to see if there is a resistance to ground from the dark green/light green wire from the injector connectors, or you use a new fuse again. Only in this way you will use a lot of fuses before discovering the problem. But check all the wires from the fuel injectors for chaving with any metal surface. Success.
It's times like this where I wish they made "testing breakers" for troubleshooting. Sometimes it would be easier to start disconnecting from the end to see when a breaker stops getting tripped.
They do make 12V DC circuit breakers (http://www.alliedelec.com/search/productdetail.aspx?SKU=677-0397).
I would recommend finding the source of the short before using something like a self-resetting circuit breaker as there is a reason that the fuse keeps blowing and you could potentially destroy something else in an attempt to find the fault.
They do make 12V DC circuit breakers (http://www.alliedelec.com/search/productdetail.aspx?SKU=677-0397).
I would recommend finding the source of the short before using something like a self-resetting circuit breaker as there is a reason that the fuse keeps blowing and you could potentially destroy something else in an attempt to find the fault.
I'm talking about something that would be temporarily used in place of a fuse while troubleshooting and trying to find the short. You could then determine where in the circuit the short is located w/out ever having to break out the meter.
Im having a very similar problem with my jeep, was there any fix that worked?
I swapped my asd relay with my pcm relay and had the same effect. It will only run when I replace the #26 fuse and only for a minute or so.
Welcome to the garage.
Does your jeep have the 4.0 engine? It seems that a thick wire bundle can have shaving somewhere on the aft side of the cylinder head.
Ok, so at this point I have visually inspected the original harness and got a second harness that I visually inspected as well as continuity tests. After replacing the original with the new harness the jeep still does the same thing. Starts, runs for a bit and dies with only the #26 fuse blown (fuel Injectors).
I have not seen any frayed wire or bare copper anywhere on either harness.
I do not understand what I might be looking for visually or why the fuse blows with a direct short somewhere.
For trouble shooting i would do the following: remove all three connectors from the PCM, remove the auto shutdown relay from the power distribution center under the hood and jumper slot 30 with 87. In this way you bypass the auto shutdown relay and put power directly to the injectors. If, with ignition in on, the fuse stays ok, then you know that the injector wiring and injectors are ok and that you have to check the wiring from the power distribution center to the PCM for chaving.
You can measure each fuel injector resistance and see if one is far lower then the others. Normal fuel injector resistance is about 14 Ohms.
The harness that you changed, is that the complete engine wire harness with fuel injector wires as well?
I bridged the relay and the fuse did not blow and I have been unable to find any area where the wire might have rubbed through. Am I looking just between the fuse block and pcm or could chafing further along the harness cause the problem.
All my injectors test at 12.5 ohms.
You put a jumper on the relay slots 30 and 87 and switched the ignition in run and then the fuse doesn't blow? I will have a look in the wiring diagram, but i think that the problem must be in the PCM.
I just had the same issue, blowing fuse 26, cranked but no start. I checked all of the wiring, replaced the CPS, ASD relay, etc. I finally disconnected the alternator and it fired up and ran fine. Hooked the alternator back up and blow the fuse. I have replaced the alternator and all is good!
This is strange, that the alternator could blow fuse 26, since its not in the circuit of fuse 26. Maybe that a problem with the alternator field winding messed with the PCM field driver and could cause a short in the PCM. Eventhough your problem seems to be a bit different then from the OP (no start at all on yours vs starting and dying after some time with the OP), its still worth a try.
My 2004 Grand Cherokee Overland had same issues. When accelerating it would blow the F26, Fuel Injector. Hard acceleration. Even revving it sitting still would do it. Disconnected the control wiring connector from the alternator and it would run fine. Just as sson as you reconnected it, and revved the engine it would blow the F26 Injector fuse. Replaced the alternator and problem was solved. I don't understand the relationship electrically except that the computer regulatd the alternator.
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