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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4402
Experience:  Owner at DJ Wilson
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I need help,transmission not engaged from neutral

Customer Question

hi,i need help,transmission not engaged from neutral
Submitted: 12 months ago.
Category: Medium and Heavy Trucks
Customer: replied 12 months ago.
is ultrashift fuller transmission
Expert:  Daniel Wilson replied 12 months ago.

Hi my name is***** will be glad to try to help. Are you getting any fault codes? Click this link for the procedure and let me know what comes up for codes. The second link is a troubleshooting guide depending on what codes you get there will be test info for each code.

Fault code retrieval

Troubleshooting guide

Customer: replied 12 months ago.
Hi, I'm not getting any fault codes. The only one I get its 25. It just gets stuck in neutral. I turn on and off the engine several times and nothing happens. It shows solid "N" on the display.When I press "drive" it makes the beep sound. This is a 2008 Peterbuilt 387, cummins engine,10 speed ultrashift.
Expert:  Daniel Wilson replied 12 months ago.

Thanks for the update. Try disconnecting the batteries for 5-10 minutes and then see if it will reset the TCM. some have been successful shifting F to R etc a few times to get it to engage. Possible causes are worn clutch brake and or clutch, loss of air on trans shifter,
bad sol valve or XYZ shifter, or faulty TCM ( computer)

Customer: replied 12 months ago.
Thanks for the help. I did disconnect the batteries,nothing happened.
Expert:  Daniel Wilson replied 12 months ago.

Thanks for the update. Ive known some to be successful letting the truck roll of on an incline to get it to engage but if not check the clutch and clutch brake, XYZ shifter, air pressure to the trans, and lastly the TCM

Customer: replied 12 months ago.
Thank you,I will try. Right now I keep it in drive when I'm parked and the gear its flashing.If I put in neutral its not going to engage again.For how long can I keep it in gear with the break applied?
Customer: replied 12 months ago.
One more thing,with the contact on and the engine stopped, I managed to put in gear but the engine would not start. Is there any way to override this and start the engine when its in gear?
Expert:  Daniel Wilson replied 12 months ago.

The engine ECM and transmission TCM both communicate this data so you would have to study a schematic to identify what pins on the ECM and TCM pass that signal and in some way supply that pin with the correct voltage to trick the ECM. I do not recommend doing this as it is a safety issue and could potentially cause damage to the modules if the wrong voltage is applied unfortunately....

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