at7615

Having trouble with a 1998.5 3500 24 valve, vin 3B6MF3666WM282782
Alternator not charging
Only gauge working is tach
Cluster will not self test (no gauge sweep )
Codes 920, 921, 999
ABS, wait to start, low fuel, brake, lights are working
Checked and cleaned all fuses, relays and connectors (PDC onleft fender and FP on left side of dash)
Pulled cluster all pins straight
Will double check fusible links and grounds this morning.

AlpineRAM

920 The cluster is not receiving a vehicle speed message from the PCM.

1. Check the PCM software level and reflash if required.

2. Use a DRB scan tool to verify that the vehicle speed message is being sent by the PCM.
921 The cluster is not receiving a distance pulse message from the PCM.

1. Check the PCM software level and reflash if required.

2. Use a DRB scan tool to verify that the distance pulse message is being sent by the PCM.
999 An error has been discovered.

1. Record the failure message.

2. Depress the trip odometer reset button to continue the Self-Diagnostic Test.


Looks like you have a CAN-Bus Problem....

HTH

at7615

Howdy and thanks, I have a scanner, i'll hook it up,


how do check software level and flash the PCM?


I.ll do the reset after the message is done


What is the CAN-bus?

at7615

Put scanner on (OBD II) scanner says can not connect?

AlpineRAM

OK, now I have a little more time.

There is a digital data bus in the truck (CAN-Bus) that connects modules like the gauge cluster, the powertrain control module, the engine control module etc in a network.
The OBD scanner also uses this bus to talk to the PCM and gets the data from there.
At the moment it looks to me that the PCM can not talk to the gauge cluster and to the OBD plug correctly.
The DRB scantool is a Chrysler tool that can connect directly to the CAN bus and that can also be plugged into the modules alone with an adapter. This enables the technician to isolate faults rather quickly.

Since you won't have this tool and the software subscription, my suggestion is that you start looking at the PCM, it is located at the passenger side of the firewall under the hood. Take a cood look for any kind of damage to the wiring.
If you do not have it yet, treat yourself to a factory service manual.

at7615

where's a good place to get digital manuals?

AlpineRAM

Print
https://www.genosgarage.com/product/...ervice-manuals

Electronic

https://www.genosgarage.com/product/...ervice-manuals

(I am not affiliated with Geno's, just a satisfied customer)