EGR - Functional Check

91audi05

Group: 26

Number: 91-04

Date: August 31, 1991


Subject: Exhaust Gas Recirculation System, Functional Check

Model(s): 80/90 w/5 Cyl and EGR starting 1990 M.Y.


The following procedure is a portion of section 26-30 of the Repair microfiche. This revision provides new resistance specifications.





Functional check

Requirement
^ EGR system vacuum connections OK

^ switch OFF ignition
^ disconnect temperature sensor harness connector (arrow 1)





^ switch multimeter US 1119 to resistance range (2 megOhm scale)
^ connect multimeter to terminals 1 and 2 of temperature sensor connector (arrow) using long adaptor wires from VW 1594 adaptor kit
^ pass multimeter and wires through passenger side window and place on seat, fasten test and adaptor wires in place using adhesive tape

^ start engine and let idle until it reaches operating temperature (radiator cooling fan comes on at least once)
^ switch OFF ignition and wait ten minutes
^ read display on multimeter must be greater than 200,000 Ohms (200 KOhms)

If NO

^ replace EGR temperature sensor


^ start engine and let idle for at least three minutes
^ switch multimeter US 1119 to 200 kOhm range
^ drive vehicle at constant speed of 50 to 60 mph on flat road for minimum of two and a half miles
^ A/C switched OFF
^ transmission selector in drive for automatic or in fifth for manual

^ while test driving, observe the On Board Diagnostic (OBD) warning light; when the light comes ON: read the resistance display on the multimeter
^ must be less than 50,000 Ohms

If NOT

^ check EGR system vacuum connections repair or replace as necessary