Speedmonster185

iTrader: (1)

I have a '93 Z28 that I'm trying to figure out a Engine light (DTC 26 code) with. I have a friend in my car club that used to have a '93 TA and he got the same code. He said he just had to replace the AIR pump and that fixed it. Is there a way I can easily test to see if my air pump is working or not?

One other thing is, someone told me to take a relay out of something like the headlights and try putting it into the spot where the relay that would be bad and set off that light would be and see if that fixes it (so all I would have to do is get a new relay for it). Where are those located? Are they in the ECM? Keep in mind this is a '93.

Thanks

2001NBMZ28

It could be the air pump or relay, but might also be EVAP or EGR related on a '93? www.fastbird93.com/diagnostics.htm

FiredUpZ28

pull the air pump completely. Code 26 is your Quad Driver Module, but it almost always means your air pump. My code kicked on when the air pump swallowed some water. Took out the pump and plugged the lines, light went out and I passed emissions. BTW this was also a 93 Z.

Speedmonster185

iTrader: (1)

If that works I could do that I suppose. Two questions though. 1. what did you use to plug up the tubes? And 2. wouldn't just removing the pump be the same thing as unplugging it, which causes the light to come on anyway?

FiredUpZ28

possibly. I just used some old drain plugs to plug the hoses (worked at Jiffy Lube lol), then tucked them away. I just figured why have a dead pump there lol.

Speedmonster185

iTrader: (1)

Ok. Well the only thing I don't understand is that I can unplug the AIR pump and it still has the light. How would just removing it completely be any different as far as the ECM is concerned as compared to just unplugging it?

Anybody else have any thoughts on this?