Normal op temp, would not start after quick beer stop, new batteries, crank over great, next morning started fine, outside temp +5 F....Code DTC 85....What is 85 please. Any ideas......?

This is an explaination from an earlier post. I know nothing about it though.


OBDI DTC 85:transmission code, Undefined Ratio

Code 85 will set if the PCM calculations indicate an unexpected gear ratio does not include overdrive. default action set line pressure to maxium.

Isn't this the code you get when the tranny's starting to slip and sticks in 2nd or third gear, but if you restart it it will shift.

My guess is the tranny code has nothing to do with why your vehicle won't start. The starting issue is likely the PMD failing on you. Fill out your sig, then copy the diagnostic checklist (located in the sticky threads at the top of this forum) into your next post, answering the checklist q's.

I used to get the code 85 but it was because I had a dual range auxillary transmission (US Gear Dual Range). When I had it in low range the ECM thought the transmission was slipping which then throws the code 85. In my case it wasn't a problem but in your case....

My guess you may have transmission issues.

thank you all, have had no problems with this truck for several years, therefore consider me a dumb swede.....I have used both High and Low range 4wd lately. lot's of snow. Code 85 will not clear by disconnect batts., What is a PMD, the tranny seem to work fine, had some trouble getting it in to 4 low, but I seldom use that......Will the tranny go to overdrive in 4 wd....?

http://www.dieselplace.com/forum/showthread.php?t=19063 :)