so i replaced the egr, egr pressure feedback sensor, and the egr vacuum solenoid trying to get rid of a code 33. When i replaced the vacuum solenoid i re-tested and had a code 84, then replaced the pfe sensor and still had the code. tried clearing the code and driving then re-testing still code 84. Not sure WTF to do

86 b2 2.9 4x4

 

Can I assume it is a KOEO 84 and not a CM 84?

My experience with these is that the computer will basically only trigger this code if it sees a full open in the EVR circuit, or a short to ground. If you take a voltmeter and trace the circuit with a volt/ohmmeter, it shouldn't take much to track it down, unless it is a CM code, in which case, the fault might be intermittent which will require more effort to locate.

 

It is a KOEO code. I am not very good with electronics. Can you give me a little lesson on how to trace the circuit with a volt meter. I appreciate any help

 

Unfortunately, I'm a poor teacher, especially over the internet like this. But diagnosing DC electronics is an important skill to develop -- cars are becoming more dependent on electronics not less.

I would first point you to the section in most Chiltons manuals that describes basic DC electricity. I'm sure there are similar tutorials on the internet, that would include the basic parts of a DC circuit (power supply, load, switch) and probably a reference to the "water analogy" of electricity.

When testing a simple circuit like this, you usually pick a good "reference" point (usually ground, or the negative battery post), and place your negative/common/black lead there. Then use the positive/red lead and start at the positive power supply (in this case, I'd probably start at the EEC relay) and probe convenient locations in the circuit to find where the voltage drops. In this circuit, KOEO, the voltage should be 12V up to the PCM (switch open). You could then use the output state test (see a good manual with instructions for the different EEC-IV tests) to close the switch for the EVR solenoid and test to see if the circuit changes states (voltage drop should move to the negative side of the solenoid).

Hope that helps.

 

Probing the circuit I found the EGR Pressure feeedback sensor is only getting five or six volts with the key on not running, is this normal? What could be the cause?

Never mind that whole system only has 5v, I checked it at the PCM, every component is getting power(5v) still getting KOEO code 84, KOER code 33. The vacuum solenoid(brand new) likes to make noise after I turn off the engine. WTF?

 

The PFE sensor's power supply is the 5V Vref signal generated by the PCM. This 5V Vref signal is used by several sensors (TPS, ECT, and others), so this sounds normal. The PFE sensor would have nothing to do with a KOEO 84, which is specific to the EVR solenoid. A bad EVR solenoid circuit could easily cause the KOER 33, so I'd suggest you focus on the KOEO 84 and the EVR circuit.

When you say "every component" do you really mean "every component," or just those using Vref? If there's only 5 V coming out of the EEC relay, then we have a bigger problem than just the EVR solenoid.

What kind of noise? The EVR is designed to have a continuous slow vacuum leak to it, so you can usually hear a "hissing"/"sucking"/buzzing sound from the EVR just after shutting the engine off.

 

When I said every component i meant the 5v Vref signal at the MAP, MAF, EGR vacuum solenoid, PFE sensor. The EEC relay had 12v at the two red wires going in. As for the EVR it makes that hissing/buzzing sound that you described. The EVR has two wires and two vacuum lines could i have the damn thing upside down? I can't find a good pic of it actually hooked up under the hood and i have seen them the other way around on other vehicles (exploders) at the junk yard.

Thanks again for all your help

 

Are you sure it only had 5 V at the EVR? According to my wiring diagram, the EVR is supposed to get 12 V from the EEC relay, and is not supposed to be wired into Vref. Double check your wiring diagram to be sure, but, if you really only have 5 V at the EVR, I would be looking between the EVR and the EEC relay for a bad connection.

 

You're right again the EVR does have 12v. Sorry, i have been doing so many tests and checks it's getting hard to keep it all straight. Do you think if the MAP were bad it might give this code? It's part of the Vref circuit, right?

 

MAP is powered by the Vref circuit, yes. But the EVR is not powered by Vref, so I would not think something in the MAP would trigger a KOEO 84. Even if it is possible, I would have it a good ways down the diagnostic tree. Way before worrying about the MAP I would be verifying the integrity of the EVR solenoid circuit.

So, we've verified power to the EVR solenoid. Now check the circuit between the EVR and the PCM. For this, I'd probably:

1) Set up your voltmeter to measure the voltage drop across the PCM at the EVR solenoid pin (+lead to EVR pin, -lead to ground).
2) KOEO, should show ~12 V.
3) Enter output state test (see any good set of instructions for the self-tests).
4) You should be able to see the "switch" opening and closing inside the computer on your voltmeter (voltmeter should jump from 12 to 0 V when closing, then from 0 to 12 V when opening).
5) This might be a good time to hook up a vacuum pump to the EVR solenoid. While the internal vacuum leak means you won't get the EVR solenoid to hold vacuum, it should be pretty obvious when the solenoid is open and closed by how easily air flows through the solenoid.

 

mrshorty

I used the output state test like you said. I tested the EVR solenoid connector pins through the back of the connector. With (-) grounded to the battery i probed the red wire pin 12v and yellow wire pin 12vv used the gas pedal to switch everything "on" probed the red wire pin 12v and yellow wire pin 12v. I have no idea what this means any insight is greatly appreciated.

 

Sometimes it's hard to tell exactly what someone is doing over the internet. If the voltage on the yellow wire never drops, that suggests an open in the circuit between the point where you are probing the yellow wire and the point where your common/negative lead is. Check the yellow wire thoroughly and make sure it is intact between the EVR and the PCM. Make sure the PCM ground is good.

 

Finally said F it took it to my mechanic. He put it on his scan tool and started getting the same codes i was. While doing KOER and checking that all the vacuum lines were good , his scan tool just started reading code 11 system pass, without changing anything. He then said he would need to keep my B2 for a couple of days to track down why it was doing that. He then asked me if i had ever had it pre-tested for smog and i told him no cause i thought the EGR fault would fail me. He told me to go ahead and do that while it was code 11 system pass. I'll be damned it passed smog.Woohoo!! Thanks to all your info i was even able to tell my mechanic a few things he didn't know about our beloved B2's.