Bad PCM?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

ARiley23

Full Access Members
Joined
Mar 24, 2013
Posts
185
Reaction score
10
Location
Michigan
Its a 98 with the 5.4.
Starts fine no issues. But the dash goes crazy sometimes. Other times nothing happens then I can hit the switch to turn on my interior lights and the dash will go back to normal but then turn the switch off the interior lights and then the dash acts up again. Sometimes the gauges will slowly lower down to nothing other times they will immediately go lower all the way down when I turn off the interior lights.
Alternator and battery are both good so nothing to do with them.
These are the codes I was able to pull with my reader. The transfer case is fine 4x4 still works tho.

Screenshot_20201217-210538.png
 

craig sargood

Full Access Members
Joined
Apr 23, 2019
Posts
367
Reaction score
142
Location
California
I believe that’s your gem module. Under the driver side dash. Common problem, windshield leaks, water gets to unit, make truck do weird things. I’ve replace mine, it’s not easy, but not terrible either
 

docraymund

Full Access Members
Joined
Feb 14, 2011
Posts
1,076
Reaction score
109
Location
philippines
Check for poor ground issues. Do a voltage drop test on grounding sites. These can be found in a dvd repair manual.
 
Top