Engine/Transmission (1998.5 - 2002) Code P1694

[pcarlson]

Guys looking thru the threads I see what this is. I was searching for codes when my ABS and brake light came on and found 1694 sitting there next to the 0500. They ABS code didn't bother me because it seems like every winter I get this code 0500 a couple times and lights always go away even after replacing the sensor still does this in the winter.



Should I be concerned with the 1694? Truck runs fine, gauges fine, and the overhead is fine. Could I have had this code set when Wally World replaced my batteries or when I reprogrammed with the Smarty?



I do notice the check engine light on the dash stays on until I start the motor but now I cannot remember when the light used to go off.



Shoot me some advice.

 

[pcarlson]

Update

Well over the holidays I disconnected the batteries and then I unplugged the ECM and PCM connectors. The connectors looked clean so I just reinstalled them. The codes are gone for now and I have only run it twice since then. The MIL bulb test doesn't go out until the truck starts so if that is the only issue then I can live with that. If it comes back I will try disconnecting and reconnecting the 11 and 14 pin connectors and see if that does anything.



Will be expensive to have to replace a PCM or ECM due to a CCD chip failure. Course I guess the problem could be in the instrument cluster as that is a possibility but a test of the cluster shows no error messages. If I had a reader I would watch the bus messages and see what is being transmitted and if there is an error. But everything the ECM is supposed to supply the PCM is there as far as I can "guess" or I would have issues with charging, gauges, driveability, etc. Plus the CCD bus has to be working or I would not be able to clear codes or program the ECM.

 

[JLandry]

As you may already know, the MIL should only illuminate for approximately 7 seconds when the ignition key is turned on. If it's staying on longer (i. e. : until the truck is started), then it could mean either a bus communication problem or the ECM/PCM is actually turning it on. If not DTC's are present, that sort of eliminates the MIL being turned on on purpose.



The MIL will also illuminate if the instrument cluster looses communication with the ECM or PCM.



If the P1694 DTC returns, that would tend to point toward an intermittent problem in the communication bus between the ECM and PCM. You would need a Chrysler DRBIII scan tool to test the bus communications.



The Dodge Diagnostic manual suggests a communication problem might occur most often in the ECM connector. They suggest checking to see if you have a good connection between pin 30 of the ECM plug and the vehicle's ground. If all else fails, they suggest replacing the ECM, but personally I wouldn't if the only problem is the MIL staying on too long before starting.



Good luck,



John L.

 

[pcarlson]

Thanks John for the insight. I will look at pin 30 and I might also pull the cluster and reseat it to see if either do anything. But you are right the only real issue right now is the light does not go out after the 7 seconds but rather goes out after start and no more codes and driveability/function is as it always was.



Do you have some more information on the wiring of the bus? The ones I have only show the ECM communicating with the cluster directly on one circuit and that is the wait to start light. The rest shows that the ECM communications going thru the PCM to the cluster. My understanding is also the diagnostics port inside the cab goes thru the PCM then to the ECM all using the CCD bus.



What are your thoughts of pulling the 14 pin connector and reseating that as well since the bus connections run thru there? I hear you on replacing the ECM I priced one from a dealer and they wanted close to $700 and online parts wants $450.



Thanks again for sharing your diagnostics manual.