P1693 no other code

[crusher773]

Ok guys 2001 model here auto trans.  Yesterday on the way home pulling a small trailer coming into a small town about 60 or so.  Got a CEL and tach dropped and then picked back up.  I pulled over and did the key flip and got P1693.  I also have a superchips programmer I keep in the truck to read codes and plugged it in and I got nothing from it.  Cleared codes with it and continued on went 80 miles or so and it had never came back on.  Stopped to eat got back in and pretty quick after taking back off at lost speeds around side streets and parking lots it came back on.  10 miles later maybe stopped again and read codes again both ways again only had P1693.  Cleared again got back in and soon as I started it came on this time.  Got home about another 10-12 miles checked again.  Same thing only P1693.  Cleared again moved aroud the yard a little and put the trailer up and unhooked and it never came back on.  Tach went wacky every time when the light popped.  Everything I have read said the P1693 is just a companion code and something else should be showing but getting nothing else with reader.  Anybody have any ideas.  Thinking maybe came sensor but not sure.  Seems like I have changed it before but I don't remember. 

[Marcus2000monster]

You need to scan with a better scanner. Sounds like a cam sensor. Just did my crank sensor and had similar symptoms. 

[Dieselfuture]

Didn't someone just talk about it in a different thread. Something about a loose cluster, just unplug it and plug it in and see if anything changes.

[Me78569]

use another scanner.   you are only getting results for CELS from 1 of the 2 computers.  The P1693 means that one computer has a code and the other computer is giving a P1693 to let you know.

[crusher773]

So I drove the truck around all day yesterday highway and in town.  First time I've drove it since having the issue was planning driving it until it popped the code and swing into Oreilly and check it.  Issue is it never threw a code and never acted up all day.  Weird but makes me lean more towards that crank sensor. 

[Guest 04Mach1]

@crusher773 I suggest using a little trick that @Mopar1973Man demonstrates in this video. It will give you ECM and PCM fault codes.

 

 

Edited December 2, 2018 by 04Mach1

[crusher773]

04Mach1 how is that any different from what I have already done?

[Guest 04Mach1]

I missed where you said you did the key flip, sorry. My thinking was your SC programmer wasn't reading the PCM. Anyhow I've never seen a P1693 without any other faults in the PCM or ECM. Maybe you have a bus communication problem in your truck where the ECM and PCM aren't talking to each other.  

 

I would look this thread over and find a scan tool that is capable of reading live data. Live data will likely help find the culprit. I hate to see people randomly throw parts at a problem and still not be fixed.

 

 

Edited December 2, 2018 by 04Mach1

[Mopar1973Man]

3 hours ago, 04Mach1 said:

@crusher773 I suggest using a little trick that @Mopar1973Man demonstrates in this video. It will give you ECM and PCM fault codes.

 

 

 

This only works on 2002 trucks. 

 

2000 and 2001 may or may not work. Most only report the PCM.

 

1998.5 and 1999 truck don't work at all.

[Guest 04Mach1]

7 minutes ago, Mopar1973Man said:

 

This only works on 2002 trucks. 

 

2000 and 2001 may or may not work. Most only report the PCM.

 

1998.5 and 1999 truck don't work at all.

My 01 will report ECM and PCM on the cluster. I'm not sure about older trucks though.

[Mopar1973Man]

2001 somewhere in the mid year some started working. This is not a guarantee that it works with all 2001. Just depends on if you got the flash to do it. Again its a random game on 2001.

[cumminsdog]

the key flip works on my 2000.

[dripley]

7 hours ago, cumminsdog said:

the key flip works on my 2000.

Does it get codes from both computers or just one?

Edited December 3, 2018 by dripley

[cumminsdog]

Don't know about which computer they come from, how can you tell ?

[Me78569]

you will see codes cycle from both computers.  00's dont do both computers  

[dripley]

Do the key trick and you should see the following for both computers.

 

p pcu, then codes, then p done

P ecu, then codes, then p done

 

If you only see one p done, you are only reading one computer, which like @Me78569 says yours should not do both unless you have an oddball.

[crusher773]

So I have driven it around on the weekends last few weeks and its done nothing except a very slight drop on the tach like 100 RPM.  When it does that it loses power but for just a split second and not enough that it throws the check engine light like it did the first time.  Some days it would do nothing at all.  I ran out to do something with it last night and it was cutting out and tach dropping like crazy.  It was bad enough last night that I wasn't sure I was going to make it where I was going and then back home.  It only does it at steady throttle just cruising.  So I got a cam sensor and put it in this evening and drove to town.  I immediately thought the truck just ran and felt better but I'll be danged if just a little ways away on the highway if it didn't cut out slightly a few times.  Nothing like it did last night but still just slightly.  It is still not throwing the check engine light.  I checked and confirmed that I do not have a crank sensor just the block off plate.  I have no idea where to look next what do you guys think?  Any ideas that I can take a look at before taking it to the shop.  I hate to keep driving it with the issue we mainly use the truck to go to motocross tracks on the weekends so lots of highway and quite often pretty decently long trips away.  I don't really want to take off with it and get stranded.   

[Dieselfuture]

I might have misread your original post, but if it's not just a cluster gauge jumping around but the actual engine is stumbling, then there are number of gremlins need to be spanked and delt with. 

Since you don't have any codes reading with scanners, I would first start by checking fuel pressure. Anywhere from 14 to 20 is it safe range, now if you have an original vp44 that may still have rubber diaphragm, 10 to 15 is a good pressure range. 

Next you need to check for AC noise, alternating current that generally comes from alternator. Then do the WT ground mod with an extra 7.5amp fuse in alternator field wire, blue in color and a separate140-150 amp fuse on charge wire.

Another thing that could be causing this is injectors or possibly a vp44 is on the way out but I would not condemn it yet, check alternator all the grounds and do the ground mod first. Doing the work is not as complicated as it sounds.

[crusher773]

I'm covered on both those FP reads a solid 16-18 and I have a noise isolator installed on the truck ac current.

[Mopar1973Man]

9 minutes ago, crusher773 said:

I have a noise isolator installed on the truck ac current.

 

Very bad idea. For sure have AC noise problem. The noise filter needs to be removed and chucked in the trash and fix the actual problem. Replace the alternator and do the W-T ground mod.