High Voltage at 5V Supply at ECM. - Dodge Diesel - Diesel Truck Resource Forums

24 Valve Engine and Drivetrain Discuss the 24 Valve engine and drivetrain here. No non-drivetrain discussions please. NO HIGH PERFORMANCE DISCUSSION!

High Voltage at 5V Supply at ECM.

Reply

 
 
 
Old 03-04-2018, 08:36 PM
  #1  
Registered User
Thread Starter
 
Join Date: May 2004
Location: Toronto, Canada
Posts: 259
Thanks: 0
Thanked 0 Times in 0 Posts
High Voltage at 5V Supply at ECM.

I am getting Cummins code 386, which is equivalent to the Dodge code P0643, as far as I can tell from reading the list of Dodge codes. Pin 10 of the Engine harness connector at the ECM, which supplies the 5V reference to the Engine Position Sensor, Manifold pressure sensor and the Engine Oil pressure sensor is seeing high voltage.

I backprobed pin 10 and my digital multimeter shows a rock steady 5 volts with the engine running. My scope, when set to a fast time base of 500 microseconds or faster shows an intermittent small sine wave of about 100 microsecond duration, about 4 cycles in that 100 msecs, amplitude of about 0.2 volts riding on the 5V reference. This disturbance occurs maybe once a second. The 4 cycles constitute a decaying waveform, the first cycle is the strongest at about 0.2V amplitude and the succeeding waves are smaller in amplitude. This small wave might not mean anything at all, I am only describing it because my scope is displaying it.

Does any one have further info on this code 386/P0643?
george7941 is offline  
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
imbodie
24 Valve Engine and Drivetrain
15
02-12-2013 09:49 AM
madhat
3rd Generation Ram - Non Drivetrain - All Years
1
01-08-2010 10:21 PM
shecom3
HELP!
12
01-27-2008 04:09 PM
OldSmokey
HELP!
0
09-18-2007 11:27 AM


Thread Tools
Search this Thread
Quick Reply: High Voltage at 5V Supply at ECM.


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.