egr - Page 2

tjzz4 · 02-23-2009, 03:12 PM

Yes.. if your coolant temp is too low the ECM will think the engine is cold and raise IAC(idle air control) duty cycle.

leolkfrm · 02-23-2009, 03:53 PM

I'm sure there is a temp switch for the ecm. the Gage is just a reading instrument

crabtruck · 02-23-2009, 06:12 PM

First things first, winchman, if tjzz4 talks, you'd do well to listen.
Very knowledgeable, no nonsense. Ten times smarter than me.

Code 34-EVP voltage above closed limit
Code 51-ECT/ACT reads -40°F or circuit open

I'd take a look at that last part first. "circuit open" aka: stuff unplugged.
If the plug is bad, loose, or wire broke, should be easy visual check.
That kind of problem would also cause the 34 code from EVP at EGR
Shorting is not a likely issue here. Follow wires where you can see them.

Could next check the ECT by ohming in place with a cold
and then warm engine to see if it's working. (engine off,sensor unplugged)
Don't remember the values, but should not be very high.

"The Exhaust Gas Recirculation (EGR) Valve Position (EVP) system
uses an electronic EGR valve to control the flow of exhaust gases.
The Engine Control Module (ECM) monitors the flow by means of
an EVP sensor and regulates the electronic EGR valve accordingly.
The valve is operated by a vacuum signal from the
EGR Vacuum Regulator (EVR) solenoid which actuates the valve diaphragm."

TESTING
1) Disconnect the EVP sensor connector. With the ignition ON and the engine OFF,
measure the voltage between VREF and SIG RTN terminals of EVP sensor harness connector.
If the voltage is 4.0-6.0V, the power circuits to the sensor are okay.

2)Reconnect the EVP sensor. With the ignition ON and the engine OFF,
measure the voltage between EVP sensor terminals EVP and SIG RTN.
If the voltage reading is 0.67V or less, the sensor is okay.

"Electronic EGR system (EEGR) is found in all systems in which
EGR flow is controlled according to computer commands
by means of an EGR valve position sensor (EVP) attached to the valve.
The EEGR valve is operated by a vacuum signal from
the dual EGR Solenoid Valves, or the electronic vacuum regulator
which actuates the valve diaphragm.
As supply vacuum overcomes the spring load, the diaphragm is actuated
lifting the pintle off of its seat allowing the exhaust gas to flow.
The amount of flow is directly proportional to the pintle position.
The EVP sensor sends an electrical signal to notify the EEC of its position.
The EEGR valve is not serviceable.
The EVP sensor must be serviced separately."

leolkfrm · 02-24-2009, 01:21 PM

Umm wouldn't it be easier to try changing the t-stat first? then all of ^^^^^^

crabtruck · 02-24-2009, 02:08 PM

No, the above is very wordy but is 4 quick meter checks, no money or mess.

leolkfrm · 02-24-2009, 02:41 PM

Ok but isn't ford like chevy, if the proper temps are not reached things don't go right in closed loop? Maybe the previous put in a lower degree t-stat?

bradrhale · 02-24-2009, 03:42 PM

the lowest ones i have seen are 160. i believe that it will still read right even at that temp.

leolkfrm · 02-24-2009, 04:09 PM

That will have to be addressed, by the forum resident ford people

, I know the later gm have problems without other modifications

crabtruck · 02-24-2009, 04:19 PM

Quote:

Originally Posted by leolkfrm

..... Maybe the previous put in a lower degree t-stat?

Quote:

Code 51-ECT/ACT reads -40°F

that's a LOT lower, where do you get those ?

02-23-2009, 03:53 PM	#12
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	I'm sure there is a temp switch for the ecm. the Gage is just a reading instrument __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

02-24-2009, 01:21 PM	#14
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	Umm wouldn't it be easier to try changing the t-stat first? then all of ^^^^^^ __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

02-24-2009, 02:41 PM	#16
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	Ok but isn't ford like chevy, if the proper temps are not reached things don't go right in closed loop? Maybe the previous put in a lower degree t-stat? __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

02-24-2009, 04:09 PM	#18
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	That will have to be addressed, by the forum resident ford people, I know the later gm have problems without other modifications __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

02-23-2009, 03:12 PM	#11
tjzz4 Senior Member Join Date: Oct 2007 Posts: 277	Yes.. if your coolant temp is too low the ECM will think the engine is cold and raise IAC(idle air control) duty cycle.

02-23-2009, 06:12 PM	#13
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,364	First things first, winchman, if tjzz4 talks, you'd do well to listen. Very knowledgeable, no nonsense. Ten times smarter than me. Code 34-EVP voltage above closed limit Code 51-ECT/ACT reads -40°F or circuit open I'd take a look at that last part first. "circuit open" aka: stuff unplugged. If the plug is bad, loose, or wire broke, should be easy visual check. That kind of problem would also cause the 34 code from EVP at EGR Shorting is not a likely issue here. Follow wires where you can see them. Could next check the ECT by ohming in place with a cold and then warm engine to see if it's working. (engine off,sensor unplugged) Don't remember the values, but should not be very high. "The Exhaust Gas Recirculation (EGR) Valve Position (EVP) system uses an electronic EGR valve to control the flow of exhaust gases. The Engine Control Module (ECM) monitors the flow by means of an EVP sensor and regulates the electronic EGR valve accordingly. The valve is operated by a vacuum signal from the EGR Vacuum Regulator (EVR) solenoid which actuates the valve diaphragm." TESTING 1) Disconnect the EVP sensor connector. With the ignition ON and the engine OFF, measure the voltage between VREF and SIG RTN terminals of EVP sensor harness connector. If the voltage is 4.0-6.0V, the power circuits to the sensor are okay. 2)Reconnect the EVP sensor. With the ignition ON and the engine OFF, measure the voltage between EVP sensor terminals EVP and SIG RTN. If the voltage reading is 0.67V or less, the sensor is okay. "Electronic EGR system (EEGR) is found in all systems in which EGR flow is controlled according to computer commands by means of an EGR valve position sensor (EVP) attached to the valve. The EEGR valve is operated by a vacuum signal from the dual EGR Solenoid Valves, or the electronic vacuum regulator which actuates the valve diaphragm. As supply vacuum overcomes the spring load, the diaphragm is actuated lifting the pintle off of its seat allowing the exhaust gas to flow. The amount of flow is directly proportional to the pintle position. The EVP sensor sends an electrical signal to notify the EEC of its position. The EEGR valve is not serviceable. The EVP sensor must be serviced separately."

02-24-2009, 02:08 PM	#15
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,364	No, the above is very wordy but is 4 quick meter checks, no money or mess.

02-24-2009, 03:42 PM	#17
bradrhale Senior Moderator Join Date: Apr 2006 Location: Texas Posts: 8,024	the lowest ones i have seen are 160. i believe that it will still read right even at that temp.