2000 Viper turns over - wont start P1389 Code

[Samhane1]

I was hoping to get some guidance. I just purchased a Gen2 and it was running fine. It would fire right up and run great. I pulled it out of the garage to do some cleaning. When I tried to pull it back into the garage - it wouldn’t start. It turns over but won’t start. When I scanned the car, it came up with code P1389 - No auto shutdown relay voltage at powertrain control module. I swapped the relay with another and the car started for a second but died. I am not sure if this has anything to do with it but I thought I would mention it. The last time I drove the car, I noticed a small amount of smoke in the front right/passenger side of the engine. I immediately pulled it in the garage but didn’t notice anything. Everything appeared fine. Here is what I observed/tested so far:

1. Battery is new
2. Ruled out alarm system
3. The fuel pump can be heard upon startup
4. I get fuel - didn’t check fuel pressure
5. As mentioned - I swapped the ASD relay
6. I validated the wiring through the fuse/relay box on the left side of the car.
7. All wiring appears good. Validated with a meter.
8. O2 sensors appear to be new. I did validate the wiring.
9. I tested for spark and it appears I am not getting any spark.

The car has full exhaust system with headers.

Has anyone had experience with this code or may know what it means or why it triggers? Any suggestions/guidance would be greatly appreciated!

Thank You!

 

[Steve-Indy]

 Did you test or swap fuse 15 in PDC since it supplies PCM and ASD?

Have you inspected O2 sensor wires to see if headers fried ghem...especially if car was sitting still while running?

 

[Samhane1]

The O2 sensor wires look good. I didnt look at the PDC Fuse. I will go check it out now. I appreciate it - will report back!

 

[LoryDROM]

make sure your battery is good.. i had a strange start problem on a weak battery, truck would crank pretty good but wouldnt start i put a brand new battery in and she fired right up.. tried the old battery again after and wouldnt start but would crank over pretty good... STRANGE

 

[Samhane1]

Hey Steve,

I did swap that relay with the low beam 20 amp right next to it. That’s the one that I swapped with and it started up for a second and then died. Any other suggestions?

Thank you!

 

[Steve-Indy]

I think that you meant to say "fuse", not "relay".
So the question now is the reason/mechanism for the shutdown..alarm vs. ASD (which will happen if no signal received by PCM from crank sensor, cam sensor, upstream O2 sensors.

After the fuse switching attempt, did you reset alarm?

Another thing to try would be to unplug, inspect, then reconnect the sensors mentioned above (one at a time) to clear micro corrosion and to firmly reseat plug into the connector if pins look OK.

Have you connected a code reader to the OBD II port to see if you can communicate with the PCM ?

Also, keep an eye on the battery voltage during all of these attempts...would use a float charger (tender).

 

[Samhane1]

I can connect to the PCM to pull the code. The ASD relay is good as well as the PCM. I swapped them both. How frustrating!!

 

[Samhane1]

I think that you meant to say "fuse", not "relay".
So the question now is the reason/mechanism for the shutdown..alarm vs. ASD (which will happen if no signal received by PCM from crank sensor, cam sensor, upstream O2 sensors.

After the fuse switching attempt, did you reset alarm?

Another thing to try would be to unplug, inspect, then reconnect the sensors mentioned above (one at a time) to clear micro corrosion and to firmly reseat plug into the connector if pins look OK.

Have you connected a code reader to the OBD II port to see if you can communicate with the PCM ?

Also, keep an eye on the battery voltage during all of these attempts...would use a float charger (tender).

Hello Steve,

You were correct, it is blowing the 20 amp #15 pcm/asd every time I try to start it. Is there a name for these larger type fuses? Do these feed the O2 sensors?

thanks

 

[Steve-Indy]

PCM provides ground for ASD relay which in turn provides battery voltage to heated O2 sensors. I still suspect your O2 sensor wires given the headers.
You can google testing procedures for these sensors...but it may be time to call Tom Sessions who is just down the coast from you in Hampstead.

 

[GTSnake]

Maybe try new O2 sensors?

 

[AZTVR]

it is blowing the 20 amp #15 pcm/asd every time I try to start it. Is there a name for these larger type fuses? Do these feed the O2 sensors?

As I read the schematics, 20 amp fuse 15 output goes to the PCM and the ASD relay. Then, when the ASD relay is activated, the output of fuse 15 is switched directly to the upstream O2 sensors and to the alternator and to the fuel injectors and to the coil packs, and to 15A fuse 1, which goes to the downstream O2 sensors. If fuse 15 always blows and fuse 1 doesn't bl0w, I would not suspect the downstream O2 sensors. A short to ground on any of the other paths is suspect and is why Steve emphasizes the O2 sensor wires (anywhere in their run) as a common point of failure reported by many people who have your symptoms, especially with headers. Note: the way I read the schematic, if fuse 15 blows with the ASD relay pulled, then the PCM line is the suspect, not the other things I mention.

 

[Samhane1]

Hey Steve/Jim,

I appreciate all the help. 15 amp fuse is fine. The 20 amp blows!!

it was the wire going to the o2 sensors. I found the short right at the frame!!! I am back up and running. Thank you very much for all your help!!

 

[Steve-Indy]

Happy to hear that you found the problem !

 

[GTSnake]

How did the wire get shorted? Did it melt against the exhaust? Or did it melt because it was overloaded?

 

[Mamba_153]

Congrats on finding the problem. Great people on this forum.

 

[andywylde]

Mamba_153, I agree. I was just reading through this thread and thinking how nice it was that people took the time to listen to what the OP was saying and help him work through the problems. Plus, the level of expertise is very high.

I've run afoul of the alarm circuit keeping my Viper from starting before and people here helped me work through it as well. Thanks to everyone here for what you do.