Engine/Transmission (1998.5 - 2002) help - ugly check engine light came on

[dresslered]

Mornin’ folks,



After starting up my truck this morning and driving a half-block, I got a check engine light, ABS light, and an Air Bag light all light up on the dash. After fueling up at the gas station, I drove it back home. The only light that remained on was the check engine light. There didn’t seem to be any loss of power (i. e. no limp mode) but over my 4 block trip, I probably didn’t get the speed up over 30. I parked it back in the garage and took the car in instead remembering what it was like when I lost my injection pump last year over highway 17. Lift pump has great pressure and the only codes displayed on the odometer are P1694/1693.



David

 

[ironbutt]

1693=A companion DTC[diagnostic trouble code]was set in ECM &PCM.

1694=Bus communication failure to PCM [Companion code]

Good luck.

 

[JLandry]

David,



P1694 originates from the PCM and indicates it lost communication with the ECM.



The best way to handle this is to get yourself an inexpensive code scanner, hook it up to the OBDII port, turn on the ignition (but don't start), clear the trouble codes, turn the ignition back off, turn the ignition back on, then check for codes again with the code scanner. If the PCM has permanently lost communications with the ECM, then the P1694 DTC should immediately return. If this is the case, try disconnecting and reconnecting the both the PCM and ECM connectors. While doing this, look for anything out of the ordinary like damaged wires, corroded pins/sockets on the connectors, etc.



After disconnecting and reconnecting the connectors, check for DTC's again. If you're still getting the P1694, let us know and we'll help you troubleshoot the wiring harness between the PCM and ECM.



Best regards,



John L.

 

[dresslered]

Thanks John. I've been through these code things before, but have never seen all the Christmas lights on the dash come on as well. I have had no luck with the OBDII scanners in the past (they've never been able to read anything from the engine). Do you have a suggestion for a brand other than the expensive Cummins or Snap-On models? TIA.

 

[SSolderitch]

I been getting those codes also for the past year +. I tracked it down to be internal to the ecm - I bought a replacement - didn't install yet. I don't throw a light with them?

the smarty shows me more codes than the cluster thing. That all that I use.

 

[JLandry]

Thanks John. I've been through these code things before, but have never seen all the Christmas lights on the dash come on as well. I have had no luck with the OBDII scanners in the past (they've never been able to read anything from the engine). Do you have a suggestion for a brand other than the expensive Cummins or Snap-On models? TIA.

David,



I'm afraid I'm not going to be of much help in suggesting particular brands of code scanners. I personally use a ScanGaugeII for my code reading and to monitor engine and vehicle info real-time. It works well at reading and clearing codes. But if I needed another code scanner I'd buy one from someplace where I could easy return it if I wasn't satisfied with it... i. e. : Wal-Mart, a chain auto parts store, etc.



Whatever code scanner you buy, don't pay extra for one that purports to list code descriptions or explain to you what they mean... these descriptions are often wrong or incomplete, and will never tell you how to fix the problem. All you need is to know the trouble code and then hit the Internet for a description. The Dodge diagnostic manuals are the correct reference for solving the problem.



If extra money is burning a hole in your pocket, buy yourself a used Chrysler DRBIII scan tool on eBay. Besides reading and clearing trouble codes, it also displays the output and state of every switch and sensor on the engine and chassis, runs all kinds of diagnostic tests, can reprogram the computers, function as a digital multimeter, an oscilloscope, and more. But it's a bit clunky and is way overkill for just reading and clearing standard OBDII codes.



Best regards,



John L.

 

[dresslered]

Thanks again John. I should prolly bite the bullet and get a scanner of some kind as my wife also has a Durango so it wouldn't be a complete waste. Appreciate all the info and I will report back when I get a chance to look at it.



David

 

[SSolderitch]

I also like the ACTRON brand.

 

[dresslered]

I had the whoe family of ACTRONs in my hands but couldn't decide which one so I grabbed a cheap INNOVA 3030. Is there really any chance that this thing will read more than the codes already displayed in the odometer (P1694/P1693)?

 

[JLandry]

I had the whoe family of ACTRONs in my hands but couldn't decide which one so I grabbed a cheap INNOVA 3030. Is there really any chance that this thing will read more than the codes already displayed in the odometer (P1694/P1693)?

It shouldn't.



It should only display OBDII complaint codes just like the odometer display. The important thing is to be sure it'll clear the trouble codes. It'll likely only be able to do this with the ignition key in the RUN position and the engine NOT running.



John L.

 

[dresslered]

O. k. , with my cheapie scanner it found the errors:

1698 (Bus comunication failure to PCM. A "Companion DTC" was set in both ECM and PCM).

1694 (which I already knew from the odometer)

1698 (repeated again).



This is as clear as mud. I guess I'll pull the DDTTPM this weekend and go for a ride. :-(

 

[JLandry]

O. k. , with my cheapie scanner it found the errors:
1698 (Bus comunication failure to PCM. A "Companion DTC" was set in both ECM and PCM).
1694 (which I already knew from the odometer)
1698 (repeated again).

This is as clear as mud. I guess I'll pull the DDTTPM this weekend and go for a ride. :-(

David,

I believe the P1698 DTC is the ECM reporting it lost communication with the PCM. Remember that the P1694 was the PCM reporting it lost communication with the ECM. Obviously there's was a communication problem between the two.

Did you try clearing the DTC's with your code scanner and have you checked to see if any return after starting the engine?

If they come back I'd definitely try removing the DD TTPM to if that makes a difference.

Regards,

John L.

 

[dresslered]

About two years ago, I got a P1693 a couple of times without any kind of clue then either. I seem to recall that something like 200-miles of driving and 20-engine starts and the check engine light and code would clear all by itself. This only happened a couple of time then I never saw it again. Almost exactly a year ago, my Injection pump died on the road and I was in a bind and had to tow it to a dealer. $3200 later, he had installed a rebuilt Bosch unit (by his word). I never knew if the previous code was related or not. Since then, I have only put about 10,000-miles on it. No other modifications since. The DD TTPM has always been on it as well as the RV275's. No other performance mods.



The difference this time around is that I got the P1694 as well as the ABS and Air Bag lights came on momentarily (as well as this new P1698 pulled from the scanner).



I didn't clear the errors just in case I end up taking the truck in again. I thought that I would recheck all connections this weekend and do a little studying up on the Chrysler Collision Detection (CCD or C2D) data bus system, and drive the truck around looking for other clues.

 

[SSolderitch]

the ccd runs from the cluster with 5v in each of the 2 wires it goes to the odbii port, abs, air bag, overhead console, transmission, radio (steering wheel controls), ecm & pcm.



you should check for voltage and for open/shorted at EACH device. There is a plug between the ecm & pcm, above the valve cover.



my truck is good (ccd voltage) - I believe it's an internal ecm issue - bought another ecm, not installed, truck runs fine.

 

[dresslered]

Thanks,

I've been reading a good article on the Chrysler Collision Detection (also referred to as CCD or C2D) data bus system and it looks like collisions are possible with bad grounds, etc. One of the common symptoms of a collision is:

• Airbag Indicator Lamp and Malfuntion Indicator Lamp (MIL) Illuminated (which I got!)

• Instrument Cluster Gauges (All) Inoperative

• No Compass Mini-Trip Computer (CMTC) Operation

 

[dresslered]

How's this for a theory?

I found this link:



YouTube - P1689 Error code found & Testing Cranking pressure



Mopar1973Man was able to generate a P1698 code by pulling the fuel system relay out of the PDC box which essentially cuts off Power to the VP44. Perhaps my relay momentarily stuck or was delayed causing the error but then obviously switched back on since the truck appears to run fine. Does this sound reasonable to anyone? Perhpas I should get a spare relay to throw under my back seat with all the other spare parts?

 

[JLandry]

Does this sound reasonable to anyone? Perhpas I should get a spare relay to throw under my back seat with all the other spare parts?

Sounds possible. But if power was interrupted to the VP44, I think you'd normally also see a P0253 DTC... who knows.



It couldn't hurt to replace the fuel injection pump relay just in case.



John L.

 

[dresslered]

According to the video above, only the P1698 code is generated (1693 and 1694 accompany it). Since the injection pump is a high current devise, I can see that pitting may have occurred on the relay contacts causing a slight glitch. I found the replacement relays (P/N 4671168E 72472M) on ebay for $9. 99. It's the best theory I got to go on especially since the truck seems to run fine. Thanks for your help.

 

[JLandry]

I found the replacement relays (P/N 4671168E 72472M) on ebay for $9. 99.

Just so you know, the relay is of a very common type and is available at any good auto parts store. It's the same type relay used for fog light kits, etc.



Regards,



John L.

 

[dresslered]

I figured that but read a few posts saying that they weren't being stocked, etc. , so I just double-clicked in the mean time. I'm going to run on my original for now.