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dead tach, speedo, and no charging

1K views 7 replies 5 participants last post by  1workinman 
#1 ·
Hi,

on my way home yesterday, the tach and speedo died and the truck stopped charging. the transmission felt like it was stuck in 3rd or 2nd gear. From other posts i'm fairly certain that i'll be needed a new pcm/ecu.

anyone know a good straightforward testing procedure for checking the pcm/ecu to make sure that it is at fault.

thanks!
 
#3 ·
Your ESS could be bad. The ess is the only thing that tells the PCM the engine is running. Th PCM can not hear the engine running without some help.


Check to see that the wire connectors are clean. One person used dielectric grease on the connections and that solved the problem. Also, use a brass feeler gauge to set the gap.





Make sure the gap is correct.
 
#6 ·
Open up the wire diagram book and check all the grounds and all the wiring from the ESS and VSS. PCMs don't fail very often. You don't have an ECU.
 
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