rvac99 Posted June 22, 2009 Share Posted June 22, 2009 I have a 2000 Legacy Outback that runs, registers the two codes for the cam sensor. The engine has no power and sounds like it is running on two cylinders. Plugs show a very rich fuel mixture and exhaust smoke and odor verifies rich condition. Temp gauge on dash fluctuates at times and from time to time the engine has run fine. Wire one (black) 19K Ohms, wire two (white) 2.6 Ohms. I have replaced the cam sensor and checked the wires from every connector and at the ECM. Wiggled all wires while engine running and added extra ground to engine and body. All wires and connectors are good, timing is right on, and I’m down to two final options: ECM or Cam sprocket. I can check the cam sprocket if I can get an old analogue multimeter from what I have gathered. I don’t believe there is anything wrong with is because everything is clean and set properly. The old cam sensor has the same resistance as the new one (2K Ohms) and the timing marks line up. Can I take the ECM to be reprogrammed or does the whole car have to be towed to the dealer? Has anyone had to replace the cam sprocket? Quote Link to comment Share on other sites More sharing options...
Cougar Posted June 22, 2009 Share Posted June 22, 2009 The two codes you gave seem to indicate a problem with the wiring to the sensor so I would check that out. Check for a wiring problem between the ECU and the sensor. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 22, 2009 Author Share Posted June 22, 2009 I did that. The wires are also sheathed and I checked those as well. My local part store gave me a print out of testing procedures for the two codes. The resistance values did not indicate a bad connection or open circuit. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 23, 2009 Share Posted June 23, 2009 (edited) Since cam sensor data is used along with that from the crank sensor to determine fuel injector pulse timing and duration, if the data is ''wrong'' (or the ECU ''thinks'' so and relies on default values) the result could certainly be a rich mixture. What Cougar suggested is proper ''by the book'' diagnosis for the P0340 and P0341 codes. However, since the cam sensor was replaced and the wiring apparently okay, there might be another possibility. I've seen reports that the timing belt tensioner can fail, causing looseness of the belt that can result in mistiming of pulses from the cam sensor and generation of the codes. Edited June 23, 2009 by OB99W Clarification Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 24, 2009 Author Share Posted June 24, 2009 I did notice some oil leaking out of the top of the tensioner. I will replace it and let you know. Thank you and Cougar for your effort. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 24, 2009 Author Share Posted June 24, 2009 New tensioner installed and still have the same problem. Just throwing the P0340 code this time. Sounds like it is running on two cylinders and the exhaust smells. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 24, 2009 Share Posted June 24, 2009 If the engine were truly running on only two cylinders, I'd normally expect more than just the cam sensor code to be set. If the ECU isn't getting cam sensor data, it will go to a fail-safe (limping) mode that uses engine speed and throttle position to determine injector operation. Did you reset the ECU? Could you be more explicit about the temp gauge variations? (Conditions, amount of change, gradual or rapid movement, etc.) It could be a problem with the ECU, but I'd suggest that you verify the cam sensor signal (pulses) are making it to the ECU input. If you can, a scope is probably the best tool for that purpose. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 24, 2009 Author Share Posted June 24, 2009 The temp. needle was bouncing up and down and then registered a higher than normal reading. This does not happen everytime I start the engine. Fluctuations did not change when I wiggled wires going into the ECM. I've cleared the ECM with my scan tool. There have been times when I cleared the codes (CEL off) and it stayed off while the engine was idling. At that time it was a normal idle speed and sound. The instant I touched the pedal the CEL came back on. Other times I have seen the CEL go off and immediatly come back on. One morning I started it and cleared the codes and it ran perfectly. I shut it off and put everything back together and it went right back to throwing the 0340 code again. I don't have a scope and heard they are expensive. I was going to attempt attaching an older style multimeter and see if the needle fluctuated evenly. Don't think I'll be able to see that much though as there are seven tangs on the cam sprocket. They will probably go quickly. My part store gave me the testing procedures for testing the wires for shorts and resistance values based on my model and code. Other than that tensioner I had narrowed it down to the cam sprocket or the ECM. I've been at this for two weeks now. Just can't seem to win with this car. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 24, 2009 Share Posted June 24, 2009 Since the problems are somewhat intermittent, it's possible that there are poor connections that you haven't found yet. The cam and temp sensors don't directly connect (respectively) to the ECU and gauge. Both of them are wired through intermediate connectors that join the engine harness with the body harness. E2/B21(gray) are a 20-pin connector pair where pins #18 & #20 are used for the cam sensor and pin #10 is for the temp sensor/gauge. E3/B22(brown) are a 16-pin connector pair where the temp gauge gets ground via pin #16. Those connectors should be near the rear of the engine, mating its harness with a body one coming through the firewall. Check them for solid contact and lack of corrosion. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 24, 2009 Author Share Posted June 24, 2009 The connectors you mentioned were my first thought. I've checked them and checked them again. I guess I'll do it again after I verify the sensor's output. I just tried it (the car) again after having the battery disconnected for 4 hours. Still running bad with a constant p0340. No p0341 anymore. I watched the temp. needle. It would go from normal range down to 0 like I had shut the key off. It jumped around like that for a few moments and then it settled on a temp. The engine was cold and the guage was indicating normal operating temp. I should get the code when I plug my reader into the connector right? My code reader could not read the code with the engine off and just the ignition on. I turned the key on first then connected the reader. Just dashed lines on the screen. Got the 0340 code only while running. I'll try the multimeter and check the connectors again tomorrow. I'll keep you updated. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 24, 2009 Share Posted June 24, 2009 The connectors you mentioned were my first thought. I've checked them and checked them again. I guess I'll do it again after I verify the sensor's output. There's one more connector to consider, a junction for sensor grounds. It's B83(blue), a 12-pin inline. It should be near the ECU (branches off the harness where the three ECU connectors do). [...] I watched the temp. needle. It would go from normal range down to 0 like I had shut the key off. It jumped around like that for a few moments and then it settled on a temp. The engine was cold and the guage was indicating normal operating temp. Are you saying that with the engine cold, the gauge indicated in a range it should only be at with a warm engine? If so, it's possible that the engine coolant temperature sensor is failing. That sensor is a 3-wire type, and has outputs for both the gauge and the ECU. It might be giving bad data to the ECU as well as the gauge. The ECU can't tell if temp data is wrong, so it might be setting parameters that aren't correct for actual operating conditions. I can't see a direct relation between the CTS and code P0340, so look at the ground junction connector before considering the CTS. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 25, 2009 Author Share Posted June 25, 2009 OB99W are you in Ithaca NY? I'm from Corning. Anyway I tested all the grounds from the ECM connectors last week. I have two sets of wire diagrams and one says I have a ground wire pos. #6 on connector B135. My wire is violet/green and goes to the defroster system according to the other set of diagrams. I can hear a relay clicking on the driver's side when I ground this wire. Is there another ground for the ECM pin connector B135? Also what does the "Shield & Sensor ground joint connector" look like. Says it is on the right side of dash. That's probably the connector that you just told me about but I had to ask. Looks like one wire grounds all those components (Shield Sensor pos. #15 WHT/GRN). Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 25, 2009 Share Posted June 25, 2009 OB99W are you in Ithaca NY? I'm from Corning. I'm actually outside the city of Ithaca, NY. Anyway I tested all the grounds from the ECM connectors last week. I have two sets of wire diagrams and one says I have a ground wire pos. #6 on connector B135. My wire is violet/green and goes to the defroster system according to the other set of diagrams. I can hear a relay clicking on the driver's side when I ground this wire. Is there another ground for the ECM pin connector B135? Ground wires are usually black, and may have a color stripe. Yes, B135 #6(black/blue) is a ground. Other ECU grounds are B134 #7(black/pink), #8(black/white) & #27(black), and B136 #21 & #22 (both black/blue). Those grounds are all routed through the E3/B22 connection I mentioned before. Also what does the ''Shield & Sensor ground joint connector'' look like. Says it is on the right side of dash. That's probably the connector that you just told me about but I had to ask. Looks like one wire grounds all those components (Shield Sensor pos. #15 WHT/GRN). That ground joint connector is 12-pin, blue, single row of contacts, and is indeed the one I referred to before -- it's effectively just a jumper. I have no info indicating anything beyond 12 pins, nor a white/green wire being a ground. I believe the common ground connection is made through the ECU itself. If all of the above checks okay, do consider the CTS. Perhaps connections at that sensor are corroded. The ECU can definitely default to a rich running condition if it's getting incorrect engine temperature data. Again, I don't see a direct relation to P0340, but sometimes the effect of a part failure isn't the expected. The uneven running might be throwing things off enough for the ECU to be seeing timing problems at the cam sensor. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 25, 2009 Author Share Posted June 25, 2009 My wire diagrams are correct for pins 136 and 134. Pin 135, 6 wires do not correspond. You mentioned that #6 was a ground and a Black/Blue wire. It is Violet/Yellow and is not a ground. #7 a Green/red wire and #28 a White/Blue showed a ground connection when I tested each wire with the plug removed from the ECM. Other wires that were incorrect on my diagram: #4 No wire #5 VIO/YEL #16 NO WIRE #17 NO WIRE #25 NO WIRE #21 is VIO/WHT #26 is BLK/GRN #28 is WHT/BLU I have a manual transmission. The blue 12 pin ground connector checked out fine. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 25, 2009 Share Posted June 25, 2009 (edited) My wire diagrams are correct for pins 136 and 134. Pin 135, 6 wires do not correspond. You mentioned that #6 was a ground and a Black/Blue wire. It is Violet/Yellow and is not a ground. My factory diagram obviously has an error, since B135 #6 is shown in one place as a black/blue ground and elsewhere as a violet/green going to the rear defogger circuit. #7 a Green/red wire and #28 a White/Blue showed a ground connection when I tested each wire with the plug removed from the ECM. The green/red wire on B135 #7 is indicated as a hot lead (via F/B fuse #11) -- you might have been measuring the relatively low resistance of a relay coil on that line. The white/blue wire on B135 #28 is shown going to a contact on the starter interrupt relay -- in that case, with the key off, I don't know why you would measure a low resistance to ground there. The blue 12 pin ground connector checked out fine. Given the checking you've done of the ECU wiring, it's probably okay. The erratic temperature gauge reading that we've discussed, however, indicates a definite problem. The portion of the CTS for that function doesn't even go through the ECU, so it should be relatively easy to track down that problem. I'd suggest looking at the sensor for a bad connection, and if that doesn't resolve the gauge fluctuation, consider replacing the CTS. Since the unit has sensors not just for the gauge but also for the ECU, it's important to use an OEM unit if you do replace it. EDIT: Because you're questioning the B135 info on the diagrams you're using, and in case what I have is accurate for the cam sensor connection, I show B135 #2(red) and #9(green) being the two pins for it. If you pull that connector from the ECU and check resistance between those two pins, you should of course measure the same as at the cam sensor itself, about 2 kohms. Other than that, I think we've run out of things to check relevant to the ECU wiring. Edited June 25, 2009 by OB99W Added cam sensor/ECU wiring info Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 26, 2009 Author Share Posted June 26, 2009 Yes the temp sensor is bad. Coolant has leaked through to the inside of the electrical connector. Just replaced this sensor in Feb. when I rebuilt the engine. I did check the Cam sensor circuit from the ECM. #2 and #9 was 1.95k Ohms exactly what it is at the sensor terminals. I agree with you, there are no more tests to run on the Cam sensor and ECM. I am very concerned about circuit that includes fuse #11 that should be hot but is acting like a ground. Could a voltage drop due to a short in the ignition cause these problems? I found 6 fuses that test for ground (0 resistance). I have the battery disconnected by the way. Fuses 5, 6, 11, 12, 17, and 18 all have 0 resistance with the ground. Fuse 5 gets power from the light system and powers and just a few light bulbs. I can’t see why it would test for ground. The other fuses all get power from the ignition and again I can’t understand why they would test for ground unless there are relays that are not labeled. Thank you so much for all your help so far. You have been very helpful and patient with me. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 26, 2009 Share Posted June 26, 2009 Yes the temp sensor is bad. Coolant has leaked through to the inside of the electrical connector. Just replaced this sensor in Feb. when I rebuilt the engine. Since coolant has seeped through the sensor, in addition to the gauge portion it's probably compromised the ECU section as well. That in itself might account for the rich running condition. The next step is obviously to replace the CTS. If the connector contacts are contaminated, of course clean them. I am very concerned about circuit that includes fuse #11 that should be hot but is acting like a ground. Could a voltage drop due to a short in the ignition cause these problems? I found 6 fuses that test for ground (0 resistance). I have the battery disconnected by the way.Fuses 5, 6, 11, 12, 17, and 18 all have 0 resistance with the ground. Fuse 5 gets power from the light system and powers and just a few light bulbs. I can’t see why it would test for ground. The other fuses all get power from the ignition and again I can’t understand why they would test for ground unless there are relays that are not labeled. Many circuits in a vehicle have loads such as relay coils, lamps, motors, etc., that will measure low resistance. Even some semi-conductor circuits will do that. Their nature changes when powered, and they don't draw excessive current when operating normally. Of course, if there were an actual short to ground, a fuse would blow. As long as you haven't changed anything in those circuits, they're probably okay. (I'm assuming the grounds you added are just in parallel with ones that were already existing.) Thank you so much for all your help so far. You have been very helpful and patient with me. You're welcome -- hopefully the problem will get resolved soon. Let's see what happens once you replace the CTS. Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 26, 2009 Author Share Posted June 26, 2009 I was hoping that I would not have to dig in there to get that CTS. Oh well, I've done everything else it seems. Going to have to ride the bike into town today. The wife has my car. Oh yes, this is her car I'm working on. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 26, 2009 Share Posted June 26, 2009 I was hoping that I would not have to dig in there to get that CTS. Oh well, I've done everything else it seems. Unfortunately, the CTS is one of the small parts on a Subaru that's a bit of a pain to change. Going to have to ride the bike into town today. The wife has my car. Oh yes, this is her car I'm working on. What, you don't have a spare (car, that is)? Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 27, 2009 Author Share Posted June 27, 2009 New CTS installed.......still have same problem......p0340. Temp. gauge on dash never moved. I don't know what to do..... Quote Link to comment Share on other sites More sharing options...
rvac99 Posted June 27, 2009 Author Share Posted June 27, 2009 My friend at the part store told me to pull the plug wires while the engine was idling. Found no change when I removed wire #3 and #4. Going to swap the fuel injectors 1 with 3 and 2 with 4 and see what happens. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 27, 2009 Share Posted June 27, 2009 (edited) New CTS installed.......still have same problem......p0340. Temp. gauge on dash never moved. I don't know what to do..... What do you mean by the gauge ''never moved''? Are you saying that it remained at the bottom of the range? If so, it's possible you have a bad connection at the sensor -- you may have to scrape the connector contacts if they corroded due to the leak. Did you get an OEM sensor as I suggested previously? EDIT: Is it possible there's a simpler explanation -- the gauge didn't move because the engine wasn't run long enough to warm it? If so, the CTS replacement may have actually resolved the erratic gauge operation. I've run across situations where there are multiple problems, but the car only gets worked on when the most recent one is bad enough so that it can't be ignored. If the driver isn't sufficiently observant, the problems are sometimes then all reported as having occured simultaneously. For example, is it possible that your wife didn't notice the temp gauge fluctuations, and the assumption has been that it's related to the other symptoms? Edited June 27, 2009 by OB99W New theory concerning one symptom Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 27, 2009 Share Posted June 27, 2009 My friend at the part store told me to pull the plug wires while the engine was idling. Found no change when I removed wire #3 and #4. Going to swap the fuel injectors 1 with 3 and 2 with 4 and see what happens. Something that's common to cylinders #3 and #4 is that they are paired in the ''wasted spark'' ignition. If there's a problem with the rear section of the coil pack/igniter, you'll get a weak or no spark on those two cylinders. It's also possible for a bad ignition wire for either #3 or #4 to affect both cylinders. Furthermore, the ECU could be failing to provide a pulse for 3&4. So that begs a question: Do you have good spark at the plug end of #3 and #4 wires? It also brings up another question: If cylinders #3 and #4 are working so badly that you find no difference in the way the engine runs when you disconnect spark from them, why isn't the ECU indicating P0303 and P0304 misfire codes? Are you sure that P0340 is the only code stored? Quote Link to comment Share on other sites More sharing options...
Cougar Posted June 28, 2009 Share Posted June 28, 2009 (edited) Rvac99, You stated in your first post that you are seeing a rich mixture, the engine is running poorly, and you have a code issue along with a possible temperature gauge issue. You also stated that cylinders 3&4 don't seem to be firing. Have you checked to see if plugs 3 and 4 are getting spark? If not make sure they are firing. For your code issue I am not real sure about what is happening there since you seem to have done the proper checks and still have a problem. One possible trouble may be the connectors to the sensors. I seem to remember one person found out that the connectors to the sensors were swapped. I'm not sure about this case though but it may be something to check out. For your temperature gauge sensor problem I noticed talk about the CTS sensor. The CTS sensor is different than the temperture sensor in case you didn't know that. The sensor for the gauge has only one wire going to it. My data shows it is a wht/grn wire. Edited June 29, 2009 by Cougar Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 28, 2009 Share Posted June 28, 2009 (edited) For you temperature gauge sensor problem I noticed talk about the CTS sensor. The CTS sensor is different than the temperture sensor in case you didn't know that. The sensor for the gauge has only one wire going to it. My data shows it is a wht/grn wire. Unlike earlier models, there is only one engine temp sensor on the 2000. It's a 3-wire, and incorporates both the ''thermometer'' (gauge) and ECU functions in the single unit. (The white/green wire is for the gauge, but there are two others.) A problem with either function naturally requires changing of the CTS. EDIT: I attached a picture of the TPS connector end to minimize any possible confusion. Edited June 28, 2009 by OB99W Added picture of TPS Quote Link to comment Share on other sites More sharing options...
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