Please help I'm at witts end. I just got 3/98 24valve and I'm trying to find out why it starts it right up, idles great and when you give it throttle in park for drive don't matter Motor doesn't go above 1500rpms . Got a code reader and it came up with what seems to be Dreaded P1689 code

Which far as.I can find is something NO ONE agrees on of the cause!!

I found this site from another diesel guy and I link I was given was here for 24valve 50\51 engine/obdii-error-codes94/P1689no-communication-between-ecm-and-vp44-r35/

 I went through link and was able to get all way to #5 test which is checking ohms between #2terminal on FORM which is Supposed to be a "White Wire" and #13 on the ECM harness connector. 

Well I don't have a White Wire anywhere in the rpms harnes. So I can't go beyond this test

At my shirts end and really don't want to have to pay mechanic $200 just to tell me what's wrong then whatever it will be on top of that. 

Really need help

 Also in reading and watching, remember something about it after fuel filter change that whatever is wrong will make it super hard to start. Getting fuel bled and fired up again. Now after changing fuel filter now seems that I'm having that issues also.( Battery started to run down so couldn't crank a lot to get fuel back up. After full day doors.open key switch on off alot .

Had to stop and charge up battery. I might get it started but still don't know why it not acting like the Raped Ape a 2nd Gem is Supposed to Be!!

Help please

Only has 113845 miles on it . Transfer pump relocated to in fuel tank. 

Not sure what other help I can give at.moment. I need help though

Like most of us I ain't got a lot in life  good wife great.daughter, he'll of a dog and not much $ especially just to have someone say it's this part that be $200 oh and if you want me to fix it, it will be X amount times 3 more plus cost of part

Y'all know the deal?

Thanks in advance for Any help

Can anyone help? Is there anyone near ft Myers florida that knows what is reason for all this trouble?

Edited March 30, 20205 yr by Eviltwisted1

It is possible the white wire is not white in your truck. Check the pins the diagnostic calls out for and ignore the wire color. There are some small discrepancies in the wiring diagrams between the years.

 

Not sure what you are speaking about changing a fuel filter and now the engine is hard to start unless the fuel system lost prime which can happen installing a dry filter. Try bumping the starter, no engine start, and the lift pump should run for 20 seconds or so. While the pump is running crack open the inlet to the VP and see if it is pushing fuel out. At least you will know the fuel system is primed. I have had that problem a couple times thru the years.

 

When you first turn the key on does your WTS light come on? It should come on as soon as you turn the key. If it is warm out it will only light for a second so you need to be looking right at when you turn the. If it is not coming on leave the switch on and see if it comes on at all. If it does then try to start it and it should fire off.

 

A raped ape is hardly a description of a stock 24v unless you have some other mods to get there. They are quite tame in stock trim. They will pull a house just not quickly.

I'll try and clear things up a little 

I was doing a test from on this forums trying to figure out p1689 code. 

There was supposed to be white wite on #2 terminal on back of vp44 connector. And #13 in 51pin on ECM

Hold that thought. In checking fuel system I changes filter. I Have Bles it All air is out of lines!

From what I think ive.learned is that the transfer pump in the tank is bad ( only has 10lbs of pressure with pump on , when cranking engine over it drops to around 5lbs( which is something else that everyone is saying g if lift pump bad it will be hell to get it started again.

So really trying to figure out Error Code P1689 .

Now I did pressure test. 

Does any of this sound correct? Right?. Am i barking at wrong part?

That's why asking for help.  I have no clue. And hate giving $$.away just to be told it's this part or that and it will be this much to fix it on top free $200.00 already paying( or lack of)

So any help would be great

9 hours ago, dripley said:

It is possible the white wire is not white in your truck. Check the pins the diagnostic calls out for and ignore the wire color. There are some small discrepancies in the wiring diagrams between the years.

 

Not sure what you are speaking about changing a fuel filter and now the engine is hard to start unless the fuel system lost prime which can happen installing a dry filter. Try bumping the starter, no engine start, and the lift pump should run for 20 seconds or so. While the pump is running crack open the inlet to the VP and see if it is pushing fuel out. At least you will know the fuel system is primed. I have had that problem a couple times thru the years.

 

When you first turn the key on does your WTS light come on? It should come on as soon as you turn the key. If it is warm out it will only light for a second so you need to be looking right at when you turn the. If it is not coming on leave the switch on and see if it comes on at all. If it does then try to start it and it should fire off.

 

A raped ape is hardly a description of a stock 24v unless you have some other mods to get there. They are quite tame in stock trim. They will pull a house just not quickly.

 

All good advice above

Run through the series of checks for vp again but use pin numbers not wire colours, these checks should test vp relay which can cause this code

As already said loosen fuel inlet at VP44 and flick the starter and see if you have fuel up to vp, you might have to do this a fair few times if you've changed fuel filter and its not bled properly. You may then need to loosen injector pipes at cylinder head to bleed these to get it to start. If no fuel at vp in tank pump could be bad ( needs to be binned anyway as even if vp is ok it wont be for long using the intank) or you could have a bad relay or bad harness. Check if pump is running first, if not check pos/neg supply for pump at the top of tank, if that is ok but pump not running pump is shot, if no 12v and earth, harness or relay or ecm is shot, if pump does run, check pressure at vp while running ideally over 14psi or thereaouts

3 hours ago, Eviltwisted1 said:

I'll try and clear things up a little 

I was doing a test from on this forums trying to figure out p1689 code. 

There was supposed to be white wite on #2 terminal on back of vp44 connector. And #13 in 51pin on ECM

Hold that thought. In checking fuel system I changes filter. I Have Bles it All air is out of lines!

From what I think ive.learned is that the transfer pump in the tank is bad ( only has 10lbs of pressure with pump on , when cranking engine over it drops to around 5lbs( which is something else that everyone is saying g if lift pump bad it will be hell to get it started again.

So really trying to figure out Error Code P1689 .

Now I did pressure test. 

Does any of this sound correct? Right?. Am i barking at wrong part?

That's why asking for help.  I have no clue. And hate giving $$.away just to be told it's this part or that and it will be this much to fix it on top free $200.00 already paying( or lack of)

So any help would be great

 

I undersrand what you are trying to do for the 1689 code. I checked a 1999 wiring diagram in the articles section here. According to it the wire should be yellow with a pink tracer on it. Is that by any chance the color of your wire? The wiring colors are not all the same for all the years. That wire in my 02 is supposed to be white. They do however do the same thing.

 

I had an in tank pump for a while. They are not very good pumps. Mine only had about 5 psi of pressure. Always cranked just fine. It is also perfectly normal for the pressure to drop 50% during cranking. The ECM does that by design. While they are not good pumps there is no reason for it to cause hard starting.

 I have had 2 transfer pump failures on mine over the years and the truck continued to crank just fine with failed pumps. The VP will pull its own fuel but its not good for it.

 

Have you bled the fuel sytem all the way to the cylinder head? Try opening 3 of the injector lines and crank the engine. If no fuel is coming out of the lines while cranking you still have air in the system, most likely from the filter change.

 

ok I have done A lot testing and checking different things. To catch y'all up. I finally got truck running again. I had air in lines and has to bleed all way to injectors. Fuel pressure is 10lbs of pressure idle or on throttle. So this is Not a Fuel issues. It is either in COM or somewhere else.

I checked APPS and it at idle was reading .729 or close to it. I recalibrated no throttle .512 or close video shows #s. So now APPS is set at the .5_Mark it needs. I have checked all wires coming off the APPS  for volt readings to check that. There is a slight hiccup/fault/hesitation I point out in video. Also after I reset APPS I also tried to clear codes. It says it cleared on my cheap reader I have. P1689 showed right back up instantly or it never cleared it.  

either way I still don't know what is wrong and why I only have idle and 1500rpms. No one seems to be able to say it's this part and you need to replace it or it is that part. 

Any help I definitely appreciate. And I thank those who are trying to help

I have not checked these readings with the truck running, but I don't see where it will make a difference.

Either I have idle or what ever it means stopping at 1500rpms. Of course turbo doesn't engage or even try to sound like it has 1 . 

 

 

So to recap, I got truck running and all air out of the lines now and she starts every time now. Now problems is same as it has been. The P1689 Code No Comma between ecm and injection pump module. .

I have recalibrated the APPS and did reset with pedal and APPS reads the .5 it needs . I tried clearing codes also but not sure if my RepairSolutions2 is actually deleting the codes or not. I don't have way to tell that. But soon as I do scan codes comes back immediately

Is there another way to Clear codes besides using scan tool? To able check if I am  getting them cleared for sure or not.. It was late by time I got some with all testing to have it running and do test for APPS while running . So I will test that today with motor running

But as of now . All test I have done and nothing seems out of whack except the APPS was off at.no throttle @.729 instead of the .5 I test it to.

When I started it last night nothing changed!!! Still have only Idle and 1500rpm at any throttle above idle. Nothing in between... Soon as I do test while motor running I'll post again. I really really have to get this figured out. I'm now e months behind on truck pay!what of main truck and they fixing to come reporting it I'm afraid. And I can sure don't have cash to pay local mechanic just to say it's this or that @ $200.00

Thank you for help this far

 

 

try changing the "fuel system relay" with the "wiper relay"  

Swapping relays might just fix a power issues which can produce a p1689 code. Might be a good time to do the W-T ground wire mod for the VP44. 

On 4/10/2020 at 10:17 AM, Mopar1973Man said:

Swapping relays might just fix a power issues which can produce a p1689 code. Might be a good time to do the W-T ground wire mod for the VP44. 

 

What is the W-T ground wire model for vp44??

What exactly is that and how.do you perform test?. I will swap relays around but pretty sure I already tried that. But I'll let yall know tonight 

Thank All of yall for trying to help me

On 4/10/2020 at 10:17 AM, Mopar1973Man said:

Swapping relays might just fix a power issues which can produce a p1689 code. Might be a good time to do the W-T ground wire mod for the VP44. 

What is this exactly and how.do I perform this? And then what does it prove 1 way or other?

I tried relay swap , that didnt change a thing.

What does the WT Mod do exactly? .meaning why is it important to do?

It improves the grounding on your computers and will lower ac voltage output from the alternator. Mine dropped considerably. It is not a cure all for any one thing just helps improve electrical system in general. I have had no electrical gremlins since doing the mod. I also not the best to explain due my lack of electrical knowledge. I do know it helped.

I have the same code P1689. 
I’ve tried swapping relays, I’ve done the W-T ground mod, just not the positive wire to the alternator as I’m awaiting a circuit breaker. 

Mine will start and run, idles great. Just won’t rev past 2000rpm. Good throttle response. 
I cleared the code, came back next start. Cleared it again and it hasn’t come back (yet). 
What I did find odd is with the grid heaters unhooked, look at the live stream values I’m getting for my ecm and injector pump voltages?  
I’m stumped so far. ?‍♂️ 

What I mean by won’t rev past 2000rpm. 
I give it a shot or two just to show you throttle response and then if you pin it....rev limits at 2000

3 hours ago, Brooks said:

I have the same code P1689. 
I’ve tried swapping relays, I’ve done the W-T ground mod, just not the positive wire to the alternator as I’m awaiting a circuit breaker. 

Mine will start and run, idles great. Just won’t rev past 2000rpm. Good throttle response. 
I cleared the code, came back next start. Cleared it again and it hasn’t come back (yet). 
What I did find odd is with the grid heaters unhooked, look at the live stream values I’m getting for my ecm and injector pump voltages?  
I’m stumped so far. ?‍♂️ 

IMG_3230.MOV

What I mean by won’t rev past 2000rpm. 
I give it a shot or two just to show you throttle response and then if you pin it....rev limits at 2000

IMG_3231.MOV

This sounds almost exactly as.mine is acting. Except mine will Only idle.og when you give it throttle it will instantly got to 1500rpms. No more no less

 I have  nothing in between rpms. And of course it doesn't come alive.or do anything except sound like diesel but that's it. Lol

Dis this mod make anychanges.as.far as.getting passed the 2000rpms? Do you have any rpms in between idle and 2k? Or does yours go straight to 2k with out being able to Keep it Anywhere but 2krpms? Like can you make it hold @ 1200rpms, or 1500? 

I'm dealing same thing so I'm curious if.you have figures.yours out yet?

 I am about.out.of choices but.to take mine somewhere,   trying to follow.5 threads here 3 on other places, and still no closer to getting it to go down street like normal diesel does. Really.piaaing me off I cant figure it out. Much less with all the these guys been trying to Help Alot. And nothing making difference on mine yet. Learned alot. But I dont know where to go from here

Eviltwistedone. I like the user name. My buddy did a lot of welding etc a few years back and called his shop twistedsteel. 

Unfortunately I’m in no position to take it anywhere, so I’m forced to continue to learn, or attempt to learn and try a little more yet before I just park it and go on with life. Sucks as we just installed a new dump box and it is the busy season for my son who uses the truck for yard cleanups, soil, rock deliveries etc. 

The W-T ground mod did nothing to help my situation, although I’m sure if I get to the point of driving it again, it may help with a few other “ghosts” 

 

Mine acts perfectly normal, pedal response, start up, off idle etc...it’s basically Just the same as If someone switched the RPM chip in a rev limiter box to 2000. 
 

I’ve got through most of ‘73s flowchart more than once, with varying results, but so far all seem okay. Waiting to borrow a different meter tonight and another set of eyes/brain with a buddy tonight that’s a electronic tech.
Everything I’ve learned from Mopar1973man and this site since buying this truck 10 years ago has never let me down yet.....I’m keeping faith before taking it to someone who condemns either the vp or the ecm without knowing for sure the problem. Look at how many posts that show...okay I spent a bunch of money and I’m no further ahead. 
Keep the faith, we’ll figure them out. ?

So while checking waiting for the other meter, I got checking for continuity between the fuel injection pump and the ECM wires. 

Pin 3 at the Injection pump should go to pin 44 at the ecm.  orange/brown at the ECM.  I don’t have continuity. 
 

Pin 5 at the injection pump and pin 33 at the Ecm. Light blue/red wire. I don’t have continuity. 
 

I’m assuming I should, however not knowing what the data link shield inj is, nor did I realize we had a knock sensor return on our motors....can’t say for certain they should have continuity until I find out what they are.

Just completed the step by step and have a problem at step 8. 
 

8. Ensure ignition is off and FPCM harness connector and ECMharness connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Black wire) on FPCM harness connector. If resistance is 5 ohms or greater, replace and program ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If resistance is less than 5 ohms, repair short to ground in Black wire between FPCM and ECM.

 

Im showing an open loop For this step. 

?‍♂️

Edited April 19, 20205 yr by Brooks

@Brooks and @Eviltwisted1 you both ought take a look at the post about ground reference for VP, ECM ect. Its in this forum and just posted. Go to page 1. This is WT's original post on the mod. It want fix your 1689  problem but is good for your electricl sytem. 

23 hours ago, Brooks said:

Eviltwistedone. I like the user name. My buddy did a lot of welding etc a few years back and called his shop twistedsteel. 

Unfortunately I’m in no position to take it anywhere, so I’m forced to continue to learn, or attempt to learn and try a little more yet before I just park it and go on with life. Sucks as we just installed a new dump box and it is the busy season for my son who uses the truck for yard cleanups, soil, rock deliveries etc. 

The W-T ground mod did nothing to help my situation, although I’m sure if I get to the point of driving it again, it may help with a few other “ghosts” 

 

Mine acts perfectly normal, pedal response, start up, off idle etc...it’s basically Just the same as If someone switched the RPM chip in a rev limiter box to 2000. 
 

I’ve got through most of ‘73s flowchart more than once, with varying results, but so far all seem okay. Waiting to borrow a different meter tonight and another set of eyes/brain with a buddy tonight that’s a electronic tech.
Everything I’ve learned from Mopar1973man and this site since buying this truck 10 years ago has never let me down yet.....I’m keeping faith before taking it to someone who condemns either the vp or the ecm without knowing for sure the problem. Look at how many posts that show...okay I spent a bunch of money and I’m no further ahead. 
Keep the faith, we’ll figure them out. ?

So while checking waiting for the other meter, I got checking for continuity between the fuel injection pump and the ECM wires. 

Pin 3 at the Injection pump should go to pin 44 at the ecm.  orange/brown at the ECM.  I don’t have continuity. 
 

Pin 5 at the injection pump and pin 33 at the Ecm. Light blue/red wire. I don’t have continuity. 
 

I’m assuming I should, however not knowing what the data link shield inj is, nor did I realize we had a knock sensor return on our motors....can’t say for certain they should have continuity until I find out what they are.

Just completed the step by step and have a problem at step 8. 
 

8. Ensure ignition is off and FPCM harness connector and ECMharness connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Black wire) on FPCM harness connector. If resistance is 5 ohms or greater, replace and program ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If resistance is less than 5 ohms, repair short to ground in Black wire between FPCM and ECM.

 

Im showing an open loop For this step. 

?‍♂️

@Brooks and @dripley I appreciate all the responses & trying to help me.

@Brooks  I've had this nickname.for 30+years now if not longer. They definitely a reason Im Called The Evil( I dont ever forget being done wrong( or right) Twisted part comes from few reasons( I'll let yall guess that part). Lol

Anyways what test are you working on where your testing black wire on VP and 5ohms and all that?? I trying to see if I did that test or not I dont remember. 

 And trust me @Brooks I am in same place. I dont have the $200 to take to my mechanic,  but if I dont hurry and get this up and running Santander is gonna come pick my New Main truck up for being past due. Was.juxt 2 months behind but with virus. Hwll I'm like 5 now, cuz lack of work( I make Concrete Beautiful overlays , patterns designs) needleas.to say I havent had.many calls for work during all this. .

Alao I dont k ow if this is allowed but if you search facebook for Decorative Coatings LLC in ft myers lee county fl(  pm me and I'll send yall my cell #) same goes for you too @dripley. If yall ever down Southwest FL yall have someone down here to help if yall ever need it. Or just hang out and have drinks!. 

@Brookslet me know what test that is and if you could upload the whole test & I'm try it also 

Dripley is this WT mod worth trying on mine? Or is it just something that I need to do just in general with No chance.in hell of it fixing mine  or is there slight chance this could straiten mine out and make it run passed 1500rpms and actually throttle up like real diesel supposed to be

 

This is the step by step I was doing. I’m still going to be at a few things. Despite having gone through it.
The Ground mod could perhaps fix it, worst case it’s all proper and it forces you to look places you haven’t where perhaps you could come across a broken or green wire etc. 

It’s not hard and only a few hours to do with minimal investment. Worst case, you get to know the truck better right lol. 
A friend of mine did the same type of work here in town. Ultimate Concrete. I worked on a few jobs with him. He just left for a job over in Cuba, Jamaica ...somewhere sunny to do the same thing before the virus struck. Good work but a niche market, especially under these circumstances. 
 

 

 

On 4/20/2020 at 4:42 PM, Brooks said:

This is the step by step I was doing. I’m still going to be at a few things. Despite having gone through it.
The Ground mod could perhaps fix it, worst case it’s all proper and it forces you to look places you haven’t where perhaps you could come across a broken or green wire etc. 

It’s not hard and only a few hours to do with minimal investment. Worst case, you get to know the truck better right lol. 
A friend of mine did the same type of work here in town. Ultimate Concrete. I worked on a few jobs with him. He just left for a job over in Cuba, Jamaica ...somewhere sunny to do the same thing before the virus struck. Good work but a niche market, especially under these circumstances. 
 

 

 

Yes definitely is a.percise market, o ly advantage is , I'm in nice warm sunny southwest fl, and all these people with more $ than sence have to have their stuff like they want it( which is good for me) , I've gotten slower last cple weeks, but FL, fixing to open up pretty quick Governor here is awesome guy and cares about normal people not just deathly. Which helps. Not only that but all theae.good ole boys down here wouldnt put up with stuff like Michigan state governor trying to do( bit no politics here for sure!)

 

Now.to Mr @Mopar1973Man

Thank you so very much for what you do for all thses guys in world who needs help. It's nice to feel community so quickly jump in to help unlike most site! So thank you for that 1st and foremost,  

2ndly, thank you for helping me. I really think I can get this fixed, and I knew there was someone,  community,  forum that could help and you have done that and more.  This is what I think I needed to track it down!. I will do the WT Mod & the other Alternator Mod i saw in same post i was tagged in.

@dripley thank you also sir! You been right there since i got on here to jump in and help. 

Now i feel i have to get it done & figured out

( with yalls help of course!) I will get these done asap( especially since not have work now) i will so the test above, see where that takes me. Then I'll post results, then do mods I guess?

What order.would yall try?

Reason asking is, that way I Know what the fix was,assuming I can get it right. If I do test repair replace, and mods all same time and it does work I won't know which was culprit. 

Or should I do mods, get that out of equation then go to test?. What yall think. 

Wither way I'll get them all done. Was trying to see priority order.

Thanks again guys for all the help. I'll work on which ever yall think 1st tomorrow and see how far I get

2 hours ago, Eviltwisted1 said:

Yes definitely is a.percise market, o ly advantage is , I'm in nice warm sunny southwest fl, and all these people with more $ than sence have to have their stuff like they want it( which is good for me) , I've gotten slower last cple weeks, but FL, fixing to open up pretty quick Governor here is awesome guy and cares about normal people not just deathly. Which helps. Not only that but all theae.good ole boys down here wouldnt put up with stuff like Michigan state governor trying to do( bit no politics here for sure!)

 

Now.to Mr @Mopar1973Man

Thank you so very much for what you do for all thses guys in world who needs help. It's nice to feel community so quickly jump in to help unlike most site! So thank you for that 1st and foremost,  

2ndly, thank you for helping me. I really think I can get this fixed, and I knew there was someone,  community,  forum that could help and you have done that and more.  This is what I think I needed to track it down!. I will do the WT Mod & the other Alternator Mod i saw in same post i was tagged in.

@dripley thank you also sir! You been right there since i got on here to jump in and help. 

Now i feel i have to get it done & figured out

( with yalls help of course!) I will get these done asap( especially since not have work now) i will so the test above, see where that takes me. Then I'll post results, then do mods I guess?

What order.would yall try?

Reason asking is, that way I Know what the fix was,assuming I can get it right. If I do test repair replace, and mods all same time and it does work I won't know which was culprit. 

Or should I do mods, get that out of equation then go to test?. What yall think. 

Wither way I'll get them all done. Was trying to see priority order.

Thanks again guys for all the help. I'll work on which ever yall think 1st tomorrow and see how far I get

Correct me if I am wrong, you only have the 1698 code right?