Boost gauge question?? - Chevy HHR Network

SS Specific Service Issues/Repairs Service/Repairs specific to the SS. Turbo-Brembo Brakes-2.0 Engine-Limited Slip Differential-Programmable Display-MU3 Transmission

Boost gauge question??

Reply

 
 
 
Old 04-08-2018, 06:51 AM
  #1  
Thread Starter
 
Join Date: 04-08-2018
Location: ny
Posts: 3
Boost gauge question??

Does anyone know for sure which MAP sensor is used for boost reference?
evotech is offline  
Reply With Quote
Old 04-08-2018, 02:16 PM
  #2  
Technical Moderator
 
donbrew's Avatar
 
Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 15,639
Neither one directly. The ECM has some sort of AlGoreithm to compute it
donbrew is online now  
Reply With Quote
Old 04-08-2018, 04:34 PM
  #3  
Thread Starter
 
Join Date: 04-08-2018
Location: ny
Posts: 3
the pressure is measured at one or both of the map sensors. Perhaps it is an average of the two. Although I would like to know for sure.
evotech is offline  
Reply With Quote
Old 04-08-2018, 05:32 PM
  #4  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 3,122
Nothing definitive, but I just disconnected the upper and went for a drive.

Gauge still worked, vacuum down to 20", but would only boost to about 10 PSI. So I think it was still accurate, but boost was limited.

And no CEL.
RJ_RS_SS_350 is offline  
Reply With Quote
Old 04-08-2018, 06:02 PM
  #5  
Technical Moderator
 
donbrew's Avatar
 
Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 15,639
The ECU uses input from the MAF, MAPs, engine speed, ambient temp, intake temp and probably more sensors to calculate the boost and torque. Then it sends a PWM signal to the boost gauge.

You could do what RJ did and disconnect them 1 at a time to see what happens.
donbrew is online now  
Reply With Quote
Old 04-08-2018, 06:18 PM
  #6  
Thread Starter
 
Join Date: 04-08-2018
Location: ny
Posts: 3
Originally Posted by RJ_RS_SS_350 View Post
Nothing definitive, but I just disconnected the upper and went for a drive.

Gauge still worked, vacuum down to 20", but would only boost to about 10 PSI. So I think it was still accurate, but boost was limited.

And no CEL.
thanks for doing that. It was very helpful to eliminating t one possible cause of my issue.
evotech is offline  
Reply With Quote
Old 04-08-2018, 06:34 PM
  #7  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 3,122
Originally Posted by evotech View Post
thanks for doing that. It was very helpful to eliminating t one possible cause of my issue.
You could tell us what issues you're having.


RJ_RS_SS_350 is offline  
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
swish43
HHR SS
6
06-22-2014 09:52 PM
InkTheFlesh
HHR SS
10
11-15-2012 02:20 PM
agentsmith23
HHR SS
6
07-03-2008 02:10 AM


Thread Tools
Search this Thread
Quick Reply: Boost gauge question??


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service