1995 leggo P0106 CEL STUMPED ? WHERE DO I LOOK NOW

[duffymaddox]

Once again I am back here asking for help. I give you a bit of history about my car. 1995 Subaru Legacy 2.2 ej22 with 145000 miles I got it for free from my sister a year ago . Right after I got it  I had to replace a MAF sensor and rerun all new brake lines. a new battery. and its been great until about 4 months ago I got a 0400 egr cel . Being that I am a noobie with no Subaru experience I was lost . But since I consider myself a self sufficient individual I refused to bow down so I got a Haynes and Chilton manual , a OBD2 reader and with the help of you guys I learnes alot about my ej22 and Subaru. So here gos  on the 4th of july my alternator died on me so I was able to get one from a buddies j-yard there was a soob there that had met it maker thanks to a semi-truck (driver side was no more) I was able to gather a lot of parts from the vehicle including a EGR ,BPT, IAC, PCV stem,and all the MAP stuff. As I said it been running with a 0400 for a while so I figured that now was the time to fix it with the help of the forum I changed the EGR and BPT  I noticed the the vacuum lines and components were pretty fouled with carbon so I decided to do a sea foam treatment, 1/3 in oil 1/3 in gas 1/3 into manifold. drove about 50 miles and then changed the oil. now I have a 0106 cel  I tried to search for the answer but I am lost. I did the troubleshooting the Haynes manual recommended .I got 4.8 volts on the ref line and when I check the solenoid I got 39 ohms well within range.

But when I backed probed the signal line I got 4.5 volts on idle but when I open up the throttle the voltage did not go down as it should and when i took the vacuum line of the solenoid i got vacuum coming in but nothing going out. I would have changed the solenoid with the one I got from the yard but they are different.(My solenoid has 2 lines on it and the yard one has 1 line and a filter) Can I remove the filter and use it anyway. I just need to know how to go about tracing the problem.

[Fairtax4me]

Don't trust info from a Haynes manual too much.

Probably just a vacuum leak. You were just messing with a lot of vacuum lines and old lines are easy to crack or break.

Double check the hose that goes from the solenoid to the intake manifold. Also check over all of the lines for the EGR and BPT valves.

 

To test the solenoid stick your head under the drivers side of the dash and find the two green plugs. Connect them and turn the key ON. This puts the ECU in test mode, all of the solenoids and relays will starts clicking and the fans will switch on and off. Stick a longer hose on the solenoid where the short hose goes to the MAP sensor. Blow into the hose and air should flow then stop as the solenoid clicks. If air flows all the time or not at all either the hose to the intake or the solenoid is clogged.

Edited July 19, 2013 by Fairtax4me

[duffymaddox]

I put in test mode and the solenoid seemed to work  I am changing out all the lines to and from the MAP.(I forgot to mention that I already changed the vac lines when I did the EGR.) Why do they have two of the same solenoids one for MAP and one for purge control? Well if this is not the issue then I dont know where to look next.

[Fairtax4me]

MAP solenoid is to switch the MAP source reading between engine vacuum and atmospheric pressure. ECU uses the same sensor for double duty. On some cars it also uses the same sensor to read Evap system pressure.

 

 

If vacuum lines don't help, check the sensor output with the engine running. Back probe the center pin on the MAP plug and compare voltage reading at atmosphere (unhook the vacuum line) and engine idle. Ground your meter to the intake manifold, not the frame.

Should have around 1.9-2.5V (or very close) at engine idle. And somewhere around 4v with no vacuum.

Edited July 20, 2013 by Fairtax4me

[duffymaddox]

I will give it a go tomorrow its dark here in Pittsburgh plus a little lighting and rain. I will go in 1st thing in the am I will let you know the results thank you very much. Like I said before I am new to Subaru's but I have always loved them. I have built 2 muscle cars with my cousin 68 Pontiac GTO judge 400 cu and a 1970 dodge Coronet Super Bee 440 magnum Hemi. This my first Japanese car and I want to get it running right so that I can eventually do some modifications and make it a sleeper......

[Fairtax4me]

Two classics! Nice!

 

I always wondered how one of these would fare with a Chevy small block under the hood...

[duffymaddox]

I have a buddy who put a 327 Chevy into a 1969 Beetle had to put engine at a angle and build a custom driveshaft. But this car is one of the fastest vehicles around . Seen him  destroy a corvette and a 5.0 mustang. crazy

Edited July 20, 2013 by duffymaddox

[duffymaddox]

This has me going nuts   I cant figure it out in test mode the solenoid works good and I have all my readings in range (ohms) but I just got about 4.7 volts at idle and no change at atmosphere the meter did not budge. do I have a bad sensor or do I have a bad solenoid or is there a freaking clogged vacuum line somewhere. I am lost .

[Cougar]

Going by what Fairtax4me states, it appears you may have a bad sensor. The info he stated was that the voltage output should be low during idle and high voltage, near 5 volts, while the engine is revving pretty high. Your info shows the opposite. High voltage while at idle or high vacuum.

[Fairtax4me]

Did you bypass the solenoid? I forgot to mention that. The solenoid may be closed preventing vacuum from reaching the sensor. Hook the vacuum line from the engine directly to the sensor.

 

Also are you sure you're checking the correct pin? Center pin is signal, ground meter to the engine block. Do not check across pins.

 

You should also check ground. Set on Dc volt check voltage on the far right pin, should be the red and yellow wire. Ground meter to the block. Should be less than .1v. Any more and you have a ground issue between sensor and ECU.

[duffymaddox]

This all started when I did the sea-foam treatment . Is it possible that the sea-foam got to the sensor and blew it up or was the sensor bad from the start and the treatment  just brought it to light. Also while running the test yesterday I left the ignition on for about 2 hours and drained the battery. So I had to put it on charge and go find other projects around the house to do . As I said before I scavenged the whole unit (sensor, solenoid, and resistor.) from  a 96 or 7 OBW so I changed out the parts. The solenoid had a filter on it where the line to the sensor should be I removed the filter and put the bottom line there. I hope that was OK. Anyway I am going to continue to test the old sensor because I got to know if it really bad. As far as the ground being the issue I tested it by accident on the first day when I was checking for line voltage . thank you guys for all your help and I will let you know latter today if that sensor or solenoid was the issue or if there is anything else. I got to take a 100 mile round trip today to visit in-laws.   So if there is still a problem then I am sure I will receive a pretty CEL for my grand prize..........

[johnceggleston]

FYI - from   http://www.obd-codes.com/p0106

 

Causes

A P0106 could be caused by:

Bad MAP sensor
Water/dirt intrusion affecting MAP sensor connector
Intermittent open in the reference, ground, or signal wire for the
MAP sensor
Intermittent short in the reference, ground, or signal wire for the
MAP sensor
Ground problem due to corrosion causing intermittent signal problem
A break in the flexible air intake duct between the MAF and the
intake manifold
Bad PCM (do not assume the PCM is bad until you've exhausted all
other possibilities)

Possible Solutions

Using a scan tool, watch the MAP sensor value with the key on, engine
off. Compare the BARO reading with the MAP reading. They should be
roughly equal. The voltage for the MAP sensor should read approx. 4.5
volts. Now start the engine and look for a significant drop in the MAP
sensor voltage indicating the MAP sensor is working.

If the MAP reading doesn't change perform the following:

With the Key on, engine off, disconnect the vacuum hose from the MAP
sensor. Using a vacuum pump, pull 20 in. of vacuum on the MAP sensor.
Does the voltage drop? It should. If it doesn't inspect the MAP sensor
vacuum port and vacuum hose to manifold for a restriction of some kind.
Repair or replace as necessary.
If there are no restrictions, and the value doesn't change with
vacuum, then perform the following: with the Key on and engine off and
the MAP sensor unplugged, check for 5 Volts at the reference wire to the
MAP sensor connector with a Digital Voltmeter. If there is none, check
for reference voltage at the PCM connector. If the reference voltage is
present at the PCM connector but not the MAP connector, check for open
or short in the reference wire between MAP and PCM and retest.
If reference voltage is present, then check for existing ground at
the MAP sensor connector. If it isn't present then repair open/short in
the ground circuit.
If ground is present, then replace MAP sensor.

Other MAP sensor trouble codes include P0105, P0107, P0108 and P0109.

Read more at: http://www.obd-codes.com/p0106
Copyright © OBD-Codes.com

Edited July 21, 2013 by johnceggleston

[Cougar]

From your comments about the sensor output voltage it seems that you aren't seeing any change of voltage while at idle or high engine revs. This can mean either the sensor is bad, but you have already swapped it out with another one, or there is a wiring problem to the sensor. The reference voltage wire is possibly bridged to the sensor output wire. Remove the connector to the sensor and then check the voltage on the sensor output lead. If you still have 4.5 volts on it then the wires are connected together at some point or there is a problem inside the ECU.