Hi I was just out with a flashlight checking all my vacuum lines due to a P1415 code and noticed a faint repeating alarm type sound coming from the drivers side firewall area in between or around the master cylinder and IAC. It was very quiet outside and thats how I noticed it, any clue as to what it is? The truck was turned off, no key in the ignition. I put the key in and turned to the first position and the faint alarm type sound continued, I turned the key to the second position and the noise continues and the IAC has a constant steady tremble also with the key in the the second position. I started the truck and could not hear the alarm type noise due to engine noise and the IAC was no longer trembling. I recently had codes read and have P1300 Cat-multiple misfire, P1590 Rough Idle code and P1415 Aux emission control (possible vacuum hose off, lose or cracked) I know from the threads that changing my spark wires to 8 mm (I ordered Kingsborne 8 mm today) should fix the P1300 as well as the P1590 (I will also be doing the ABS mod repair using option B) but would any of these codes cause the repeating faint alarm sound? I cannot hear the noise at all when I walk to the passenger side and listen for it.

Thanks in advance,
Aaron 717.645.1328

 

Wires alone won't necessarily fix a 1300, probably will need plugs also.
As for the 1590, go get your codes read first, yes a ground wire repair is important, while you have it off, you should replace the shuttle valve and o-ring assembly along with what other fault codes show up.

 

When you say "alarm sound" is it a beep, a siren, a buzz, etc? A vacuum leak can make a whistle that might contuinue after truck is off for a while, depending on the vac resivoir for the SAI. The whistle or tone might come from wherever the vac line is routed.

 

Is the sound on the driver's side almost like an electronic stopwatch ticking quickly? If so, it is coming from the ABS modulator. Normal. I can go down to my vehicle in the garage that has been turned off since 10PM last night, raise the hood, and the sound will be there. You can test by unplugging the single black wire that plugs into the engine side of the modulator to see if the sound stops. Years ago, I was alarmed by this sound thinking it was going to cause battery drain, but the vehicle firing right up after setting in an airport parking lot for over a week eliminated that fear.

Several other people on this forum have reported the same noise from the modulator with the vehicle off, key in pocket.

 

Mine makes the same noise. It is VERY faint. I tried to track it down for a while as well and worried about the battery, but it does nothing to it (or minimal). My will go used for 2 weeks at a time sometimes and no issues at all. I only remember it when I am changing the oil or working under the hood.

 

Thanks guys for the reply...

Mike I did my plugs about a month ago, I had NGK Iridium plugs in and they made my truck run poorly so I switched to NGK G-power plat plugs. I'm hoping the new 8 mm Kingsborne wires will fix the 1300. Im am just doing the ABS mod part B this weekend cause the shuttle valves etc wont be here for a week so I will just have to pull it off again. I have time this weekend to do it so i might as well. Wires should be here next week and that job looks like a royal pain in the ***...

Savannah its like lordmorphes said and I did unplug the ABS mod and it went away. I take it that is a normal sound for the ABS mod to make?

 

Also code 1415...I found a vacuum hose that connects to the master cylinder and appears to run back where the coil pack is but it is broken off. I took pictures of it but am not sure how to post them to a thread...any advice on posting pics to a thread?

 

I came back to this thread after searching around for some other things. Is this the line you are talking about? Would be good for others to comfirm it is supposed to be this way. I'm not sure it is or not yet.