2005 chev trailblazer ls 4.2 air pump and sol are new all fuses and relays test ok ,air pump relay is also new ,but all will not turn on -----------I need help!
NEED HELP SAIS pump problem
- Thread starter daisey
- Start date
I believe the best option is to do the Air Injection Delete. But I will let someone who knows more about this system chime in. Mine does not have it.
Mooseman
Moderator
This is a very trouble and failure prone system and we usually recommend to delete it.
Removing Secondary Air Injection System
Air Check Valve delete parts: GM 2574378 & GM 24577193 ...
SAIS gasket (Reasons to delete SAIS and tune)
If you need to keep it for e-test reasons or by choice, you need to do more troubleshooting. Are you getting any codes?
Removing Secondary Air Injection System
Air Check Valve delete parts: GM 2574378 & GM 24577193 ...
SAIS gasket (Reasons to delete SAIS and tune)
If you need to keep it for e-test reasons or by choice, you need to do more troubleshooting. Are you getting any codes?
code po410 & o2 sensor down stream I replaced 02 sensor and pump & valve only tofind no power to either, all fuses and relays are good I don't know where to go from here.
Mooseman
Moderator
No. You need to have your PCM tuned to eliminate the associated codes but that will be done forever.
Sounds like it's an electrical issue, possibly broken wiring.
Sounds like it's an electrical issue, possibly broken wiring.
Mooseman
Moderator
I have downloaded schematic for circuit but what it does not tell much .does the pump relay supply power to sol valve when activated?
power is always at those devices. the pcm only provides a ground to cause operation. As suggested, test for power at the fuses and go from there. what fuses are you testing (ie. numbers). The system is relatively simple electrically... operational / maintenance wise maybe not so much.
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pump fuse relay fuse & pump relay @ fuse panel, I replaced relay at pump , the old one looked good just in case : thank you for helping me!
Mooseman
Moderator
I am very curious about those stinking chassis grounds,I have alwase had problems for over 50 yrs. I will let you know what I find. thank you!
Some "Mouse Crawling" may still be in order to Locate, Unfasten and Clean the Ground contact at the G-107 Position:
gmtnation.com
Electrical Ground locations
While troubleshooting a bad ground I came across some scans of the service manual regarding electrical ground locations for our platform posted on another site. This includes both short and long wheel base, as well as both 4.2L and 5.3L. Credit goes to Wex...
gmtnation.com
all connections at fuse box read 12v,I cleaned what ground stakes I could locate ,still no results-- I will check interface connections am. also new code appeared 02 heater on new sensor I just replaced I am spinning my wheels with this thing.
FWIW... If the SUV was used for Regular "Boat Ramp Activity"; especially around Salt or Brackish water and the SUV Chassis was submerged deep enough or sufficiently splashed to cover the SAIS Pump mounted quite low on the Frame, in time it could Rust Up or sustain a Black Plastic Casement Leak creating a Short Circuit within the Secondary Air Injection System Pump Motor.
Voltage and grounds checks are only the first step. From the posted circuit diagram, a simple resistance check from the 87 contact pin in the relay holder / socket of the pump relay and similar for the solenoid relay socket will likely tell you more about the health of the wiring and said units, electrically. No crawling required. Go from the result.
I had a problem with sais a few years ago..did you check the relay next to the pump under the car..i went crazy trying to figure it out and i just happened to notice the relay under the car..iirc its not well protected and was just rusted and rotten
i replaced the relay-----------------there was nothing wrong with old one. my problem is no power to pump or sol valve had to walk away ,may have to farm it out.
i did a voltage check on relay ,inboard right to left 12.25 -12.25 outboard right to left 0---1
OK... so you have voltage going towards the pump relay... I am assuming the way that you have typed it means both contacts have 12.25v as opposed to one has 12.25 and the other has -12.25. As suggested, you need to do a resistance test (to a known ground) for the other "non-voltage" pins.... this will tell you if the wiring going towards the pump AND thru the pump is good... INCLUDING the contacts at the pump connector. Again, no crawling is needed at this point.
NOTE: you also have to do the same checks at the SAIS solenoid relay as it works in conjunction with the pump... solenoid action then pump.
NOTE: you also have to do the same checks at the SAIS solenoid relay as it works in conjunction with the pump... solenoid action then pump.
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OK... that is a VOLTAGE test... you need to do a resistance test... that will indicate the condition of the electrical paths.
post 26 tells you which pins you need to measure. set you meter on resistance, red probe on the pin in question (in the socket of the fuse block) and black on a known ground. The reading will tell you how much resistance there is thru your motor to ground IF there is an electrical path which you can readily see in the posted diagram. The same tests can be done at the solenoid relay socket.
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in feb this year i did a battery replacement when i put neg cable on I noticed a flash & spark what I thought was quite unusual ,since then all of these problems have arise now it seem like alt output is low 12.75 volt meter on dash is like a clock in ff.this thing is a money hole.alt is 7 yr old.---------------------------lost