LS1LT1 Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
124 Posts
Discussion Starter #1 (Edited)
I've got a 100% stock 93 T/A A4. I'm getting code 26 (QDM 1 error), but no clue what could cause this on a T/A. From what I've found i can only find 1 QDM errr, but from other threads I've read, there are multiple QDMs. Any clues or help would be helpful.

Thanks everyone


Sent from AutoGuide.com App
 

·
Registered
Joined
·
1,298 Posts
QDM Driver #1, the '93 bundled circuit checks, any one of following 3 failing resulting one DTC 26. The ECM activates the air pump relay, EGR solenoid and EVAP solenoid by grounding one side of the relay or solinoid. When activated it looks for 0 volts to the activation circuit, and when NOT activated it looks for +12 volts on the activate circuit. So an open wire, missing solenoid or relay, blown fuse, or defective (open) relay or solenoid can cause this DTC. You need to start checking fuses, then get a voltmeter out and verify +12 on BOTH sides of each solenoid/relay with ignition on and engine off. If OK then you have to go back and verify same at the PCM end. Do the first check and if it's OK let us know, as checking PCM end requires more wiring pin locations we can give you.
 

·
Registered
Joined
·
124 Posts
Discussion Starter #3
So it's definitely something in the air pump circuit. Fuse was blown, put in a new fuse, which blew within 5 seconds....


Sent from AutoGuide.com App
 
1 - 4 of 4 Posts
Top