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03 TJ - No Start (Cranks) - Help

6K views 42 replies 6 participants last post by  pipeburn 
#1 ·
Need some help!! 2003 Jeep TJ I6 4.0L won’t start and doesn’t seem to be getting fuel or something. It turns over fine when you crank it but won't fire up. Initially I got error codes 1595, 138, 442, 455 and 1494. I was looking at the rear vacuum canister and noticed a bunch of melted hoses (see pictures) back by Fuel tank EVAP hoses behind rear passenger tire. Going to replace these as it seems concerning. However, now these codes are all cleared for some reason and getting P1282 and P1388. Been checking a lot of threads and posts and doing some basic diagnostics. All fuses and relays seem to be working fine. Also replace Crankshaft and Cam Position Sensors. Looking at the grounds and they seem good. Any help for extra root causing and figuring out this issue is appreciated. Also going to try to figure out how to check the fuel pressure as maybe something with fuel pump... I can hear it click when the key is turned on so is that what it sounds like when it turns on? I would rather figure this out and learn than send it to a mechanic to fix. 🤬😤😠😭
 

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#2 ·
the new codes (P1282, P1388) are likely your no start. they are Fuel pump and ASD relay issues.

Do you have wiring diagrams And are you comfortable doing elec work- using a test light, DVOM ?
 
#3 ·
I am ok at checking wiring and doing elec work and have a volt/ohm meter. I have the service manual for the 03 from another forum topic. I did check for power through the ASD and Fuel Pump relay with key off and on and both were good and replaced them with another relay that was good and those were ok. What other items do you suggest?
 
#6 ·
Make sure fuse 12 in the fuse block behind the glove box is good.

Besides power to the PCM it also powers the ASD & FP relay energizing coils.

P1282 Fuel Pump Relay Control Circuit An open or shorted condition detected in the fuel pump relay control circuit.

P1388 Auto Shutdown Relay Control Circuit An open or shorted condition detected in the auto shutdown relay circuit.
 
#7 · (Edited)
I have the EVAP diagram but thanks... going to replace the all the EVAP lines... just need to know if I need to replace the fuel pump too if I drop the fuel tank...

I checked fuse 12 and it is good... I checked all the fuses and they all seem to be good... what is the easiest way to check if I am getting fuel pressure?
 
#39 ·
no start issue

do you here the fuel pump come on?? i had the same problem in may when i was doing the final stages on my 97 build and for some weird reason in the front fuse compartment pdc there was a 30 amp fuse that was roasted,put a new one inn and she fired right up but what gave it away was the fuel pump was staying on because of the fuse problem!,
 
#41 ·
no start


i feel for you on the tank cap giving you trouble because even though my tank cap was tight when i reasembled my full frame off restoi some how didnt tighten the main fuel line hose clamp that goes from the rubber onto the steel and it causes a automatic shutdown thank god but when i first heard it i had just figured out my no start issue and then heard the gas spilling onto the old wooden post and beam floor man did my heart drop to my knees,and it was a ***** trying to get a long 1/4 drive and ratchet with 2 inches of height and this did this to me twice but now its been fine!.
 
#10 ·
Are you still getting those 2 codes?

Check fuse 9 in the PDC as you did for the others.

Check to see if you are getting 12v power to fuses 12 (fuse block) & 9 (PDC). Fuse 9 should have 12v to it key off & 12 with key on.

If both are good, pull both ASD & FP relays, check both for 12v at terminal 30 (A15 & C10) which would be from fuse 9. If good make 2 short jumper wires & jump both relays from terminal 30 to terminal 87 (A14 & C 9).

That should get the FP pumping & also power the coil pack & injectors. Try starting it with the jumpers in place. If it starts you will have to pull the ASD jumper to shut the engine off. Pull the FP one too.

If that works you will know the problem is the relays are not being energized (clicking closed) when starting.

If it starts, next check for 12v (key on) from fuse 12 for each relay, at A13 & C 6. If good, the last check is if the PCM is grounding the relay coils. Check terminals A11 & C 8. They need to show grounding for about 2-3 seconds when you first turn the key on & also when you are cranking the engine.

That pretty much checks the circuits related to the P1282 & P1388 codes which can cause crank, no start.

Here is a shot of your PDC to locate the terminal listed for the ASD (A) & FP (C) relays.
 

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#11 ·
I did the first part of this and both fuse 12 in fuse box and fuse 9 at PDC were good and showing volts as you suggested to check. I am somewhat new to checking these terminals and don't understand which ones to check next as I pulled the ASD and FP Relays... where is terminal 30 and what does A15 & C10 location mean? Please help as maybe I am missing something or overlooking something... thanks for the help....
 
#12 ·
I know this can be very confusing but you are doing OK so far.


OK, look at the diagram I posted above. That is part of you PDC where the relays are. Find the ASD (lower left corner) & follow the arrow. It points to the relay socket. Labeled R1 & has the terminals numbered 13, 11, 14 & 15. The relay is in row A (labeled just to the left of the PDC above the ASD arrow. So A15 is terminal 30 (often printed on the side of the relay). That is the one that should have 12v from fuse 9. When the relay closes it connects 30 to 87 which is A14. Putting the jumper between those 2 will send 12v to everything on the ASD circuit (coil & injectors, etc.) as well as to the PCM. Not seeing 12v there will set the P1388. Bypassing it this way will bypass the circuit that energizes the relay to connect 30 to 87 in case the problem is in that circuit (A11 & 13). & if doing this along with the FP relay causes it to start we know where to look next.

Now follow the fuel pump arrow to that relay socket, note it is in row C & has terminals 6 to 10. So C10 is terminal 30 which needs 12v (I missed that 12v comes from fuse 23 in the PDC so you need to check that fuse if no power to C10). Then jump C10 to C 9 to bypass the relay to power the pump.

See if it starts.
 
#13 ·
Wow, thanks for walking me through this. That all makes complete sense now. :smile2: So, with the key off, I went out and did these checks on the ASD and the FP relay. The ASD did have the 12V from terminal 30 (A15) to fuse 9. However, when I checked the fuel pump relay it did NOT have 12V from terminal 30 (C10) to fuse 23. I tried to bypass jump them anyway and still got crank but no start. Seems like something is wrong with power getting to fuel pump relay if I am not seeing 12V between this and fuse 23. Again, the ignition was off for both of these checks. What to check next? :frown2:
 
#14 ·
OK, assuming the fuse checks good with the meter & both terminals in the PDC fit tightly to the fuse legs & also there is 12v to one of the 2 terminals there has to be a break in the wire between the fuse & relay socket. You can lift the PDC & flip it over to check that. I have occasionally seen wires at the crimp-on terminal have corrosion causing voltage loss or even a broken wire.

One thing you can do just as a test is to run a wire from the battery (+) to terminal C 9 of the FP relay to power the pump. Then see if it starts. Try with the ASD jumped & if it starts that way pull the jumper & put the ASD relay in & try again. If it still starts you only have a lack of FP power & then can find the cause under the PDC.
 
#15 ·
Ok, so now I tried the jumper from the battery (+) to the C9 of the FP Relay and still got nothing with vehicle on or off. I am assuming this is bypassing the fuse too so I didn't need that in. Still nothing. I used my multimeter to check for volts from battery (+) to C9 of FP relay and no volts. I did make sure the fuse and relay for the ASD were plugged back in as well and still nothing. :confused::mad: I feel like we are doing so really good root causing here but strange we can't get there yet. Does this mean I most likely have a short in the wiring in the back of the PDC or somewhere else...
 
#16 ·
When you put 12v from the battery directly to C 9 that should power the pump & you should be able to hear it running unless you have an open wire somewhere. You getting a code saying the PCM is not seeing FP relay output makes me think it is in the relay circuit & normally when that happens bypassing the relay gets power to the pump.

I would say lift the PDC & inspect the wires to/from the FP relay including the dark green/black one going to fuse 23. Also make sure the dark green/white wire is coming from the C 9 terminal to be sure the FSM has the order correct.

From there the C 9 wire should go to the back powering the pump. You could be sure there is 12v back there.
 
#17 · (Edited)
Just to double check but per my picture below this is how I should be checking for 12V across the battery to the fuse 23 and then to C9 of the Fuel Pump Relay if I see 12V here which I don't. Tried key on and key off and nothing... am I doing this right. :confused: :brickwall

Also, I checked for continuity from battery (+) to the C9 for the fuel pump relay and I am am seeing continuity (see picture below).... what am I missing...
 

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#18 ·
No, you need the black on the battery (-) & the red on the element you are checking which becomes the (+) contact. Even if you reverse them you will just get negative but otherwise accurate readings. What you cannot do is connect to the battery (+) unless you are looking for a ground. In that case the black meter lead goes to the (+) & the red to the element being checked.

Not that bad. Just start back at the beginning with black to (-) & check for 12v. Start at the C10 & A15 to verify fuses. If good, then jump to C9 & A14 & try to start.

If not starting go back to the very beginning. Let me know from there.
 
#20 ·
Thanks for the walk through again! Appreciate the Help!!! So I have power to C10 & A15 but no power to C9 & A14 when I turn the ignition to On position or Off. I tried a jumper wire between them (C10 to C9 & A15 to A14) but wouldn't start either an no fuel pressure per my gauge I have on there when key in On position. Could there be an issue in the harness all the way back to the fuel pump that would be causing this? Just thinking of other things??? Also, seen some posts regarding the ignition could be causing certain electrical issues and I know my ignition seems loose and key comes out in any position. :brickwall
 
#21 ·
OK, the ASD will not allow the FP to pump after 2-3 seconds with the key on but should pump when cranking so if no pressure, jump only the ASD & add fuel to the throttle body while cranking. If it starts even for a few seconds you have spark, a good thing. If you can carefully add fuel (preferably gasoline) slowly while holding the TB open it should keep running. Just try that for several seconds. If good, try putting the ASD relay back in & see if that will allow it to start & run briefly. If good you will know the ASD/PCM are good & probably the FP relay will work too but the FP is likely bad. You could jump the FP relay & check the dark green/white wire at the FP for 12v. If good there but no pressure, the pump is bad.
 
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