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positive needs to be on 2 or 5 or both. you can try different ground pins for the negative side. Maybe we can get them to work?
I think the more circuits you make, the further it should move. Still, if the valve is not new, it sounds like it might need to be replaced. Were the two that moved new parts?
That should be right. A few seconds should be enough to test the motor without burning it out. The link “College Man” posted on the other thread indicated the ground should be modulated, or turning on and off rapidly.
The fuel pump relay circuit malfunction code (p0230) and the random, or multiple cylinder misfire (p0300) are now present.
A regulated voltage would be present at the coolant temperature sensor, crank position sensor, throtttle position sensor, etc. The alternator should give you unregulated voltage, often around 14v.page 13A-64 shows the Idle speed Control Valve uses the additional connectors to increase idle speed when the air conditioner is running. As always, the last choice is to replace the ecu, and have a dealer reprogram it. so I would try to jump 12v power and ground to the valve while disconnected to prove it is good, then check the harness for continuity. From your other post, I think you are getting all the right signals from the ecu. Full time 12v power on pins 2&5 comes directly from a fuel injector relay anytime the key is on. Grounds on 1,3,4,6 depending on whether the ac is on or off come from the ecu. Page 13A-169 show a modulating ground controls iac position. easiest seen on a scope, but shows as an average, probably around 5-7 volts on a multimeter.
I think all 4 pins, 1,3,4,6 should show 12v with the multimeter connected to battery positive, but the engine must be running, so the computer can determine how many of the circuits should be operating. if some of the pins have a good ground, 1,6 the valve should be at least partially opening. You might be able to confirm this by unplugging the connector and using jumper wires to connect pin 2 to battery positive and either 1 or 6 to battery negative for a moment to see if the valve opens.
If this is correct, you should get grounds on the terminals 1,3,4 & 6.
http://www.club3g.com/forum/maintenance/140906-how-testing-iac-idle-air-control.html#/forumsite/20491/topics/140906?page=1That probably explains almost no voltage on pins 3 & 4. Try testing these from one of the powered pins using a pin to backprobe the connector while the IAC valve is plugged in. The car should provide more grounds as idle speed drops and less grounds as it increases. You should read a full 12 v on the working grounds, if not you need to check for continuity to the computer and any of its grounds. I wouldn’t expect .15 v to operate the IAC valve. Test again to try to verify the poor connection to the computer and look for wiring harness integrity.
Long trips? More than 1/2 hour on my truck will set this p0420 code. But black smoke isn’t good either. It may be getting too much fuel or running “rich” a scanner with live data could help, but making sure the temperature sensor and oxygen sensors are connected might be a good start.
Also if the exhaust smells like unburnt gasoline that might be another clue.Looks like all the sensors are out of range sometimes. Does your code reader app give you freeze frame data? Maybe it can tell you what kind of conditions preceede the unusual readings. I suspect the 5 volt reference the sensors use is fluctuating and might be related to either the charging system, battery, or the computer. If the codes never set the check engine light, maybe the computer is resetting itself too often for the codes to be confirmed so they are all pending codes. Freeze frame info might tell us if it’s happening most at stop lights, etc.
This diagram suggests the IAC may have 2-3 power feeds if it is a 6 pin connector. It should get a ground to turn it on from the ecm. Probably 2 12 v inputs, and a 5v monitor with signal or control going back to the ecm. Not sure which wire controls the actual solenoid. You might try unplugging the valve and trying 12 v power with a jumper wire to see if it functions normally. If it works, you might have a weak ecm ground or too much resistance in the wire.
Most vehicles in North america and europe have a port on the lower dashboard to attach an obd II code reader to read trouble codes stored in the engine computer.
You’d need access to the scanner for the obd connection to read the codes.
You can still check fuel pressure with a gauge that fits on a port on the fuel rail that is about the size of a tire valve. You screw the fuel pressure gauge on, and then read the pressure when the engine is running. Usually around 50 psi. Or 344 kpa.The throttle adjustment screw should be holding the throttle open by 1/4 turn past contact just so it doesn’t get stuck.
Seems like the TPS may have a separate idle adjustment, or is it a second component?
http://www.dsmtuners.com/threads/differant-tps-adjustment-methods.103936/http://www.dsmtuners.com/threads/throttle-body-install-question.332674/#post-151826306
I think the screw on the throttle body is only a part of the adjustment, moving the switch in and out is the other part of the process.
But by all means try adjusting the screw first.Lack of compression could cause the dead cylinder, but I would expect it to turn over easier, instead of locking up. Think it would leak the fuel into the exhaust and or oil and coolant.
Also, I think the injectors are switched by the ground, so there should not be a ground present except for a brief moment in the intake stroke.Do you get voltage to the idle air control valve when the throttle is closed? If you have a mechanical throttle linkage and idle air control valve on the throttle body as I expect, it is possible the IAC valve isn’t opening.
Another problem with vacuum leak like symptoms can be caused by the egr valve.I replaced the timing chain tensioner after it failed at 107k on a ’98 Altima. The tensioners are hydraulic, working off oil pressure. If your oil pressure is good, and the rattle comes from the timing chain and not the lifters, you may need to replace the tensioners and probable the chain and head gasket.
When the tensioners go, the timing changes enough to make the engine sound like a diesel!
