My rainier has failed emissions test again. replaced all secondary air system [,pump, check valve, relay] 2 years ago when it failed . I now have same problems again . Checked pump works fine off 12v source , no water in lines check valve should be ok , replaced relay and checked all fuses ok . Pump still does not start up on cold start . Also replaced o2 sensor at exhaust manifold . Any one have ideas . Thanks Mike .
05 buick rainier
- Thread starter mikezuz
- Start date
Welcome!
What specific code do you have? I assume it's the one for the SAIS diagnostic.
If the pump doesn't run on a cold start, but works on a bench, and you have a new relay, then I'm thinking it's a corroded relay socket, bad crimp on wiring near the socket, or the fuse you think is good that feeds it really is not, or the ground to the pump is not good. Have you checked the relay socket with a meter to make sure voltage gets to one socket position?
What specific code do you have? I assume it's the one for the SAIS diagnostic.
If the pump doesn't run on a cold start, but works on a bench, and you have a new relay, then I'm thinking it's a corroded relay socket, bad crimp on wiring near the socket, or the fuse you think is good that feeds it really is not, or the ground to the pump is not good. Have you checked the relay socket with a meter to make sure voltage gets to one socket position?
Bill, code P0410 has been the trouble spot but another one just came up last night C0055 . That one was in the history but never saw it before . The relay socket was corroded 2 years ago , cleaned it as good as i could & put dielectric grease in sockets , looks clean now . Have not tested it , not quiet sure how to do that since they say it only runs for about 15 sec. on cold start . I'm not much of mechanic , but have time [out of work bricklayer] .Any help would be greatly appreciated . Thanks Mike
The relay should look like this:
View attachment 31640
Contact 30 should have 12V on it at all times, fed from front fuse 56. When people check fuses, they often skip these large J-case fuses around the edge of the fuse block. Contact 87, another wide blade onthe relay, goes to the SAIS turbine pump. Jump these two locations inthe relay socket and the pump should spin. If it doesn't, check for voltage at the socket, and then check for a good ground on the black wire at the pump.
If that works, then the relay has a problem at the control side. Contact 86 should have 12V when the ignition switch is in the RUN/START position. If you turn the ignition switch on but don't start the engine, then when you put your own ground on contact 85 of the relay, the relay should actuate and the turbine should spin. To check a signal on a wire when the relay is connected, I often use a safety pin poked through the insulation as a tap, then put the meter lead on the pin.
View attachment 31640
Contact 30 should have 12V on it at all times, fed from front fuse 56. When people check fuses, they often skip these large J-case fuses around the edge of the fuse block. Contact 87, another wide blade onthe relay, goes to the SAIS turbine pump. Jump these two locations inthe relay socket and the pump should spin. If it doesn't, check for voltage at the socket, and then check for a good ground on the black wire at the pump.
If that works, then the relay has a problem at the control side. Contact 86 should have 12V when the ignition switch is in the RUN/START position. If you turn the ignition switch on but don't start the engine, then when you put your own ground on contact 85 of the relay, the relay should actuate and the turbine should spin. To check a signal on a wire when the relay is connected, I often use a safety pin poked through the insulation as a tap, then put the meter lead on the pin.
Attachments
Bill, pump works jumping term.30 & 87 . With key on term. 86 shows 5-8v term 85 to ground nothing . So is relay bad ? Thanks Again.
I'm back last thread wasn't quite accurate term 30 gave me a 10.5v reading , but when jumped to 87 pump did run. With key on term 86 showed 10v.+ also , but term 85 to ground did nothing .So is socket bad & if so I haven't been able to find part . Is socket replaceable by pulling blue clip off ? Will wires come out ? Thanks Again Mike
Are you measuring the voltage from term 85 to ground? I meant you should put your own jumper from term 85 to ground to force the relay to close. If you put the jumper from 85 to ground, measure the voltage on term 86 at the same time. If it's around 10V, then the relay is bad. If it droops to near ground, then the wiring from the relay coil fuse to the relay is bad, or the coil fuse. Did I post the number of that one?
I've never changed a relay socket, so that detail eludes me. Sorry.
I've never changed a relay socket, so that detail eludes me. Sorry.