Engine/Transmission (1994 - 1998) P1389 Code, Need Help!

[bmw54]

Hello , i have been away for awhile from the TDR but i am back.

Still have the same issue with the P 1389 code . it is not the relays.

checked them.

someone out there had the same code come up?.

How did you fix it?.

 

[Missouri Mule]

1389 code for 96 and up is for "No auto shutdown (ASD)relay output voltage at PCM"



Is your voltmeter working? If the voltmeter is working then the ASD relay/wires/connectors should be working. If not check engine speed sensor connectors/wires between engine speed sensor/ASD relay and PCM.



Is your tach working? If not could be engine speed sensor/connector/wires.



The engine speed sensor activates(energizies) the ASD relay which then sends voltage(line voltage) to PCM/(EVR=electronic voltage regulator). Apparently your PCM is not getting this voltage. Check to see if you power going to the relay. There should be a fuse that supplies power to the ASD relay in the PDC.

 

[Bob4x4]

Hello , i have been away for awhile from the TDR but i am back.

Still have the same issue with the P 1389 code . it is not the relays.

checked them.

someone out there had the same code come up?.

How did you fix it?.

It is an erroneous code in most cases

 

[bmw54]

tach is working. volt meter is working. could it be a bad electrical connector somewhere?.

 

[Missouri Mule]

If your tach and voltmeter are working the PCM is receiving signal from ASD relay. Probalbly a bug in the PCM.

You could check connections but I wouldn't worry about it.

 

[bmw54]

I checked the connections at the heater relays under drivers batt and found corrosion
on all 4 bullet connectors. cleaned those up and looked for others.
I think yes it could be a bug in PCM, truck runs and starts fine.
Thanks to all for your help.