PLEASE HELP NO GAUGES NO BUS

[FlatsKing863]

This is my first post on here guys, I’m in dire need of your help. 8 days ago I had a rebuilt transmission with a shift kit and triple disc converter put in the truck; a mile into the test drive all gauges were lost. Inline Performance figured out that it was a bad PCM and put a new one in it. 

 

Today I had to run home for something and left the truck running in the driveway for no more than 10 minutes. When I came back out, no gauges we’re working but the tach, the odometer is reading No Bus and the transmission won’t shift out of 3rd unless manually done. Please give me ideas, I feel my case is different than a lot of other no bus threads on here seeing as I just replaced my PCM less than 2 weeks ago

[Mopar1973Man]

Error codes?

 

There is something going on with the PCM. The PCM is the master computer which starts the CCD Network without it the cluster will throw a No Bus message and then the gauges don't work. 

 

Possible P1698?

 

 

 

[JAG1]

I sure hope you find it. You put a lot of money in that truck. I would be checking rechecking all connections to the PCM. Especially groundings. Check the one going to the passenger battery negative from the PCM. That gey connector goes loose inside and can't tell when because of being in cased in grey plastic. The PCM ground to the firewall is probably important as well. I wish I could be more helpful.

[FlatsKing863]

I will check all grounds and for codes and get back to you guys. I appreciate the help

[pepsi71ocean]

16 hours ago, FlatsKing863 said:

This is my first post on here guys, I’m in dire need of your help. 8 days ago I had a rebuilt transmission with a shift kit and triple disc converter put in the truck; a mile into the test drive all gauges were lost. Inline Performance figured out that it was a bad PCM and put a new one in it. 

 

Today I had to run home for something and left the truck running in the driveway for no more than 10 minutes. When I came back out, no gauges we’re working but the tach, the odometer is reading No Bus and the transmission won’t shift out of 3rd unless manually done. Please give me ideas, I feel my case is different than a lot of other no bus threads on here seeing as I just replaced my PCM less than 2 weeks ago

 

I went through the same issue even I first had my built auto put in. It was wired wrong and there was a voltage regulator installed into the wiring harness. Well we cut the power supply to the PCM and it would do that if we turned on the heater circuit. 

 

In short you need to find what is causing the PCM to shut down. My guess is that there is a wiring mishap here causing it to turn off.

[FlatsKing863]

3 hours ago, pepsi71ocean said:

 

I went through the same issue even I first had my built auto put in. It was wired wrong and there was a voltage regulator installed into the wiring harness. Well we cut the power supply to the PCM and it would do that if we turned on the heater circuit. 

 

In short you need to find what is causing the PCM to shut down. My guess is that there is a wiring mishap here causing it to turn off.

Okay I will check there as well. Checked grounds and replaced one to no avail. I got codes 920, 921 & 999

[Mopar1973Man]

2 hours ago, FlatsKing863 said:

I got codes 920, 921 & 999

 

Ummm... Those are cluster codes. Another issue to itself. 

 

I need you to plug in an OBDII code reader and then report back the error codes. Don't bother with the key trick it's not reliable. 

[pepsi71ocean]

1 hour ago, Mopar1973Man said:

 

Ummm... Those are cluster codes. Another issue to itself. 

 

I need you to plug in an OBDII code reader and then report back the error codes. Don't bother with the key trick it's not reliable. 

 

Do this then check the back of the instrument cluster. They was a tsb for one of the plugs. 

[gipperkid]

Do you happen to know if the wait to start indicator is flashing?

[Mopar1973Man]

22 minutes ago, gipperkid said:

Do you happen to know if the wait to start indicator is flashing?

 

ECM internal error. Most likely going to require sending the ECM for repair.