Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

EGR Temperature Sensor: Testing and Inspection

1. No EGR operation with engine warm:
a. Check hose routing and EGR solenoid operation.
b. Remove center connector from CTS and wait 90 seconds.
c. If EGR operation now resumes, replace CTS.
2. EGR operation with engine cold:
a. Check hose routing and EGR solenoid operation.
b. Remove center connector from CTS and check for 10 ohms resistance between center terminal of CTS and ground.
c. If ohmmeter indicates an open circuit, replace CTS.
d. If ohmmeter does not indicate an open circuited CTS, check for open circuit in the CTS to engine ground wire.

NOTE: When replacing CTS switch, do not torque more than 60 inch lbs. Overtorquing will break off the nylon threads in the intake manifold.