How do I diagnose E49 (AIR problem)?

GREEN HORNET

MEMBER
1990 CADILLAC SEVILLE
80,000 MILES

Car's on board diagnostics shows e49 (AIR problem). My Chiltons says nothing about the AIR. Also the car tests very high on CO and hydrocarbons but seems to run okay w/o obvious missfire. Noticeable fuel smell after start-up. No info on driveability (it's a friends car and we didn't take it for a ride. Preliminary inspection of hoses and connectors found nothing obvious. Help appreciated, friend has very low income. I have some mechanical experience with other makes.

4 Replies

CADIEMAN

MECHANIC
3,544 POSTS

The air pump needs to be replaced. There is a pully and its run by the fan belt. Look it up to get a pic. Then u will see what it looks like.

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Monday, May 28th, 2012 AT 9:16 PM

WRENCHTECH

MECHANIC
20,761 POSTS

Replacing the air pump is a bit of a stretch on this one.

DESCRIPTION:

This diagnostic test monitors the AIR system to detect operating problems with the Electric Divert Valve (EDV) and Electric Switching Valve (ESV). It performs these tests using the oxygen sensor and ECM integrator function to monitor valve function. This switch valve has a 2 pin connector and is located behind the cruise control servo bracket. The divert valve also has a 2 pin connector and is atop the AIR switch assembly.

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Monday, May 28th, 2012 AT 9:44 PM

GREEN HORNET

MEMBER
2 POSTS

Thanks for the prompt reply. How do I enter the ecm output cycle? I checked the voltage across the connectors mentioned with a high impedance digital multi meter. Got a steady 12volts nominal. I assume the ecm produces the pulsing voltage as a testing aid. Also, I found the ecm but couldn't id the various connectors. Is there a drawing that would help with this? Standing on head, poorly lighted conditions!
Thanks again!
Walt

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Saturday, June 2nd, 2012 AT 6:36 AM

WRENCHTECH