Dtc26
Thread Starter
Teching In
Joined: Apr 2009
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From: Richmond, Texas
Dtc26 LT1 fans,
My car ('93) is throwing this code after sitting for several months. I was getting an EGR code after driving at steady speed for about 30-40 minutes. Book said it was the EGR solenoid, so I replaced it. I put everything back together but managed to leave the connector to the ignition controller near coil unconnected. Car wouldn't start as expected. I tried several times to figure it out, but never noticed the connector. That's why the car has been sitting for months.
Anyway, I finally noticed by "moron moment" and connected the plug. Now I am getting the DTC 26 which in my book shows is a quad driver error. The QD runs the evap purge, EGR solenoid, and air pump.
Ideas?
I don't think it's the EGR solenoid because I am not getting that error anymore. Replace the other solenoids? No experience with this quad driver part of the ECM.
My car ('93) is throwing this code after sitting for several months. I was getting an EGR code after driving at steady speed for about 30-40 minutes. Book said it was the EGR solenoid, so I replaced it. I put everything back together but managed to leave the connector to the ignition controller near coil unconnected. Car wouldn't start as expected. I tried several times to figure it out, but never noticed the connector. That's why the car has been sitting for months.
Anyway, I finally noticed by "moron moment" and connected the plug. Now I am getting the DTC 26 which in my book shows is a quad driver error. The QD runs the evap purge, EGR solenoid, and air pump.
Ideas?
I don't think it's the EGR solenoid because I am not getting that error anymore. Replace the other solenoids? No experience with this quad driver part of the ECM.
Thread Starter
Teching In
Joined: Apr 2009
Posts: 7
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From: Richmond, Texas
I'll test the EVAP purge since that seems the most likely culprit. I'm "assuming" my EGR solenoid is good. Hope it's not the air pump 'cause it's tight over there. When I get the code I can hear something turn on, which I might be the air pump. Sounded like my fans to me. I have an open Borla on my car, so it's hard to hear much besides that.
Thanks for the tip.
Thread Starter
Teching In
Joined: Apr 2009
Posts: 7
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From: Richmond, Texas
- Checked resistance on my purge solenoid - ~26 ohms
- Bought a new purge solenoid - 36 ohms, swapped it out
- Measured voltage on the connector with key on = ~12 VDC
- Measured resistance on my new EGR solenoid - ~56 ohms
- Checked voltage on the EGR connector with key on = ~12VDC
-Found my vacuum hose to the fuel pressure regulator was loose, pushed it on all the way.
Cleared the error and started the car, but after 2-3 minutes the error returns. When it does, the I can hear fans come on. I can't see which, but I think it is probably the coolant fans. I have not checked the air pump, but I think it may be coming on. Need to check voltage on the connector to the relay.
- Bought a new purge solenoid - 36 ohms, swapped it out
- Measured voltage on the connector with key on = ~12 VDC
- Measured resistance on my new EGR solenoid - ~56 ohms
- Checked voltage on the EGR connector with key on = ~12VDC
-Found my vacuum hose to the fuel pressure regulator was loose, pushed it on all the way.
Cleared the error and started the car, but after 2-3 minutes the error returns. When it does, the I can hear fans come on. I can't see which, but I think it is probably the coolant fans. I have not checked the air pump, but I think it may be coming on. Need to check voltage on the connector to the relay.
Thread Starter
Teching In
Joined: Apr 2009
Posts: 7
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From: Richmond, Texas
Update:
Checked the solenoids for continuity on the EGR and the purge. Both checked out good.
I replaced the purge solenoid just because I had a new one.
Measured voltage on each connector and had ~12 VDC on each with key on, engine off.
Checked the air pump fuse in the fuse box behind the driver's headlight. Found it blown.
I replaced the fuse and started the car. After a few minutes, the fans kicked on again and the CEL lit up again.
Checked the fuse, and it was blown. I figured the air pump was bad. Tried measuring continuity on the pump with the connector removed and found what looked like an open.
Hooked up some wires & switch to the pump. As soon as I connected the wire to the battery, and got a spark, so I figured it was a short.
Ordered a new one ($$), installed it, and replaced the fuse.
All is well so far. No CEL.
In this case, the air pump was bad.
Thanks to the contributors to my thread.
Eric
Checked the solenoids for continuity on the EGR and the purge. Both checked out good.
I replaced the purge solenoid just because I had a new one.
Measured voltage on each connector and had ~12 VDC on each with key on, engine off.
Checked the air pump fuse in the fuse box behind the driver's headlight. Found it blown.
I replaced the fuse and started the car. After a few minutes, the fans kicked on again and the CEL lit up again.
Checked the fuse, and it was blown. I figured the air pump was bad. Tried measuring continuity on the pump with the connector removed and found what looked like an open.
Hooked up some wires & switch to the pump. As soon as I connected the wire to the battery, and got a spark, so I figured it was a short.
Ordered a new one ($$), installed it, and replaced the fuse.
All is well so far. No CEL.
In this case, the air pump was bad.
Thanks to the contributors to my thread.
Eric
