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P1694 Code - No Fuel, No Start, No Nothing

T

TerraWombat

NAXJA Forum User
Location
Eastern Shore MD
I've read some of the threads regarding the P1694 codes, but my particular issue doesn't seem to fit. Most say the CPS is bad and has shorted, but a multimeter shows no signs of this.

'98XJ w/AW4. Gauges don't work when the key is in the 'on' position, but the mileage shows on the odo and I never get a 'no bus' message. Unplugging the CPS shows no change in the gauges. Truck also isn't getting any fuel - fuel pump never kicks on...can't hear it come on and there is 0psi measured at the rail. Truck does crank and I'm not sure about spark. Even unplugged the three connectors from the computer on the drivers side inner fenderwall and still didn't get a 'no bus' message on the odo - I was sure that disconnecting the computer tripped that message...

Any ideas? By the way, this is on an XJ that I'm looking at picking up, so I don't have immediate access to it.
 
Thanks for that article. Wish I would have pulled that up when I went searching on my phone for possible answers. I was under the impression that the CPS is only bad if it's completely shorted, which it was not, although I do think I was getting some resistance when I was measuring the pins...I'll have to play with my multimeter and figure out what the numbers mean when it's on 'continuity' mode. I was definitely getting number between 600-1000 when I was testing for continuity.
 
You should get a 3-second prime through the ASD relay when the key is first turned to the ON position. After 3-seconds the PCM will cut off the relay and the pump will stop.

If you are getting NOTHING at the pump when you first turn the key to the ON position, start testing at the ASD relay.

I have not seen it, but reports of a shorted CPS/CKP giving a "no bus" or an inability to read codes--scanner won't find the PCM when connected.

I would verify spark first, then try and find out why there is no power to the pump.
 
Is the ASD relay that you're referring to the one on the passenger side of the engine bay under the black plastic casing with all of the other relays/fuses? That was the first spot I checked. What I should have done was swap out the relay with my '01 XJ I had with me, but hindsight is always 20-20...and if the truck were somehow able to fry my '01 XJ relay, I would have been stranded.

I'm not getting a 'no bus' at all...not even when the computer is completely disconnected. My scan tool was able to read the P1694 code fine, although the check engine light was never illuminated. One thing I did find strange was that when I went to erase the P1694 code, my scanner wouldn't let me do it because it thought the engine was running! I had to put the key into the 'accessory' position for it to erase the codes.
 
Just try swapping your relays around, they are all the same part number. You should have three or four of them, just mark them so you can put them back where they started.
 
joe_peters said:
Just try swapping your relays around, they are all the same part number. You should have three or four of them, just mark them so you can put them back where they started.
Click to expand...

Yea, shoulda done a lot of things while I was there - always seem miss the obvious in the 'heat of the moment.' Like I said - this was an XJ I was looking at buying, but didn't want to fork over the cash until I had a solid idea of what may be the problem. Spent about a half hour trying to diagnose it, but came up with nothing. Wish I could go back tomorrow and try a couple more things before I put in an offer on it, but we're expected to get hit with 6-14 inches of snow.
 
Update: Wound up buying the XJ Sunday morning and had to leave for NH Sunday night (made a pit stop in CT to watch the SuperBowl).

I had a hunch that the problem may have been a blown #11 fuse on panel located on the interior fuse block. I pulled that fuse on my '01 XJ and was able to replicate 2 of the three major symptoms I was observing with the '98 XJ, which was no voltmeter or fuel gauge and no power to the fuel pump. Couldn't replicate the P1694 code - my code reader just kept saying it couldn't connect to my computer once I pulled the fuse.

So, I arrived on Sunday only to find all of the fuses were fine, but I swapped the #11 fuse out for good measure - still nothing. Decided to get the truck anyway since the body is in real good shape and the thing only has 71K miles on it. Also has a brand new windshield, brakes, shocks, and battery. I think the combined cost of all of those parts are probably more than I wound up paying for it. I had roughly one hour to work on it before I had to leave for NH, but I'll summarize what I was able to get done.

1. Unplugging the crank position sensor DOES NOT give me my gauges back. I tested the resistance between pins A and B, B and C, and A and C. Each test gave a reader of anywhere between 1000-1250 ohms. According to the link that was posted earlier in this thread, there should be NO ohm reading at all and it should be a completely open circuit on all of the pins? Am I understanding that correctly?

2. I swapped relays around like they were playing musical chairs. Even took my known-good relays from my '01XJ and swapped them in - no changes.

3. ALL fuses, both on the interior panel and in the underhood power distribution center are GOOD.

4. Although I knew this was likely a bad idea, I did it anyway as I was desperate and needed to figure out an answer quickly. I swapped my '01 ECU into the '98. They should be different in a lot of respects since the '01 has FOUR O2 sensors and coilpack ignition. Naturally, when the '01 ECU was swapped in, it threw codes for non-existant O2 sensors (duh) and some other emissions control thing. The P1694 code also came back, but here's the kicker - my volt meter and fuel gauge came back! Still nothing from the fuel pump and I didn't have time to check if I was getting voltage back to it as it could be bad and not kicking on at all. What seems odd is I sometimes get a little drip coming from the fuel bleeder valve if I push it open after many attempts at trying to get the thing started.

So, from my very brief testing, it would seem to me the ECU may be bad, but I'm not convinced and that's a lot of money to spend without really knowing. I may trade XJs with my girlfriend and get the '99 since they should have more similar ECUs. Also, while I'm thinking of it, the current ECU in the '98 also does something kind of silly. When the P1694 code is read on the scanner and you try to erase it, it won't let you because it says the engine is running! Well, that's obviously not the case since I can't get the darn engine to run! If you hit retry on the scanner, it will then erase the code no problem.

Anyone have any other suggestions? Obviously, I need to test for power at the fuel pump - that'll be my first test when I get back, but if there is anything else or if any of my testing notes from above seem odd, let me know!
 
It sounds like the engine is probably flooded. And have you checked for spark yet? Don't forget, spark plugs tell stories, pull the plugs and see if they're are fouled and how.
 
Also, did you put a new Cps in yet? If not, do so.
 
Ok well you need to rule things out. 1. Check for spark. 2. Check for fuel with a fuel guage. Replace that damn cps lol
 
TerraWombat said:
I have not, but are you 100% sure it's bad given the results of my ohm readings?
Click to expand...

Yes, replace it. There's a reason why that code was thrown.
 
Are you sure your harness isn't burned or cut somewhere. Codes indicating shorts and sensors getting unplugged and showing good, I would give a hard look at the interconnecting wiring. I'm tired, but that is the first thing that comes to mind.
 
Jeepcherokeeboy97 said:
Ok well you need to rule things out. 1. Check for spark. 2. Check for fuel with a fuel guage. Replace that damn cps lol
Click to expand...

1. Will do when I return home at the end of the week.

2. 0psi at the rail with my gauge. I just mentioned the dripping of the fuel because it seemed odd that fuel was somehow getting from the tank to the rail...like the pump worked for a split second - anyway, irrelevant, I guess. Forget I said it.

Jeepcherokeeboy97 said:
Yes, replace it. There's a reason why that code was thrown.
Click to expand...

I'll probably get one anyway for a "spare." Actually, I think I'll take my multimeter to a parts store to see what a brand spankin' new CPS measures.

westvirginia24976 said:
Are you sure your harness isn't burned or cut somewhere. Codes indicating shorts and sensors getting unplugged and showing good, I would give a hard look at the interconnecting wiring. I'm tired, but that is the first thing that comes to mind.
Click to expand...

This is something I will have to check out. I had about an hour to troubleshoot the car before I had to leave for a business trip so testing each harness wire wasn't really an option.

I thought I had this in the original post, but I guess not. An additional piece of info from the previous owner: The Jeep was running fine when he got it and were replacing a few items on it prior to an inspection. Went out to start it and the battery was dead so he used a jump-pack on it to get it running. Decided to get a new battery for it and when he replaced it, the truck no longer started. Turned over, but wouldn't fire. My initial thought was that he replaced the battery with the key in the 'on' position and blew out a fuse or two, but they all checked out good. Actually, there was a blown 25A fuse (one of the larger ones) on the passenger side floor when I went to look at it. Seems like it had been replaced since all of the fuses on the panel tested good.
 
i think you should ask him which parts he replaced on it to get it inspected.
 
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