Mil on with no trouble codes
I don’t ask for help often but today I am. This job is for an old friend. He owns a shop about 70 miles from me. He delivered this one to me so I wouldn’t have to keep traveling back and forth.
The concern is the MIL is always illuminated. There are no codes stored in any module. Full system scan shows 7 modules (ECM, ABS/VDC, Airbag, TPMS, Integ unit mode, Occupant detection system and CAN system) This is a manual trans so no TCM on this one.
The customer has a donor vehicle that had the same IPC. Videos show both clusters doing the same thing. ECM part numbers checked with dealership parts department. Numbers match for the VIN.
I have a couple questions about the diagram I found on this one. There is an option of a C6 or except C6. I would like to know what that is and how to tell if this vehicle has the option. There is also an option for luminescent meter or normal meter. According to the diagram I have posted the placement of the engine light designates this as a normal.
Does anyone know if this effects the way the ECM commands the MIL on? The reason for this question is the fact that the wire that is shown on pin 38 of the cluster doesn’t exist on this vehicle. It isn’t on pin 33 on the B135 connector of the ECM either. I connected a test light to B+ and tested the pin 33 cavity with no wire in it. Results are in the videos. I get the expected key on bulb check and a change in state when I induce a code. The other wire shown is pin 32 of the cluster and 15 on B135 of the ECM gry/red wire. When I scope that wire it has a momentary 12 volt signal when the key is cycled from off to on. Then back to zero. When you start the engine it goes to a constant 50% duty cycle. Clean and crisp zero to 12 and back equally spaced pulses. This doesn’t change with a code or not present in the ECM. I also checked the CAN wires at the IPC. They are perfect looking CAN patterns. I checked the pattern at the DLC and compared side by side. The same packets were at both ends. I did try to overlay a wire from pin 38 at the IPC to 33 of the ECM to see if it would change anything. Nothing changed.
Here’s to hoping someone has some idea what I’m missing here and is willing to help.
I would first look at the PCM request for the MIL. If not requesting, then you might have a cluster configuration issue.
Go on obd and check there if its saying mil off to .just as to eliminate a voluntary command of the mil by ecm.
With the flag as off, the drive is not being commanded on. I would interrogate the IPC for an output check. See if there is a command for out puts. One last item, if automatic verify that there is not a command for a code, which would illuminate the MIL.
Have you tried using Global obd2 or possibly another scan tool.
Yes I have used three different scan tools on this vehicle. Sorry I forgot to mention that. Obd generic has also been checked.
Like some others have said I would try another scan tool if you haven’t tried that yet as well as the OBD2 generic side as I have been bit by that one. Also you mentioned another donor vehicle have you checked if it have a 12v square wave on that circuit on the donor when running also? I was just checking on a identifix and they have the Subaru factory test for mil on doesn’t turn off no dtc…
The donor vehicle is not a running vehicle. It suffered a life ending front end crash. OBD generic was looked at. I failed to mention that as well as several other scan tools also.
C6 is a transmission option. If its manual it is "except", as the C6 is an automatic transmission.
Perfect thanks Keith. How would I know how to find that information?
Not sure, I'm just familiar with Ford nomenclature.
I wasn’t aware of Subaru using Ford parts.
Looking back now, I have no idea what I was thinking lol. Completely disregard what I said..... must of been a late night.
If you haven't yet, check EGI B+ fuse in underhood main fuse box.
Hmmm, thinking out loud, I noticed in the video of the Combination Meter that the Cruise light goes out, typically IF there were a code being generated/stored it would flash. See if you can induce a code. FYI, Combo meters have to be registered to the BIU (Body Integrated Unit.) I haven't swapped any post 2010's, so I'm kinda surprised it didn't code in the BIU.
I am aware of the need to register the cluster. I am able to do that. Thats how I got it to work.
In OBD2 Generic, what does the PID "Distance traveled while MIL is activated" read? I have had weird issues with several Nissans and MIL operation. Attached is an article I wrote about one Nissan that was failing due to the MIL command from the PCM but had no actual MIL illuminated. It sounds like you almost have a logic problem between modules. Have you tried to clear codes in the IPC and PCM…
I will look into the distance traveled. I did do a reset as well as clear codes. I feel like the counter probably got reset when the battery reset was performed.
I'm thinking along the lines of trying to prove if the ECM is commanding/requesting the MIL. If you have anything besides 0 miles for "Distance traveled while MIL is activated" then I would say that the PCM appears to be turning on the MIL even if the request for the MIL shows as no. If you are unable to get that data PID to read 0 miles by clearing DTCs and disconnecting the battery then I…
I will look at this again when I get back to the shop. Looks like it’s going to be this evening. Friday’s are always my busiest mobile days.
After 3 miles of driving with the orange glow.
OK, so it seems that the MIL request and distance traveled while MIL is activated are in sync. with each other-no request and no counting upwards. Can you set a code now and see if the MIL request changes to yes and the counter increments when you drive it. If that works correctly then I would tend to think something else besides the PCM is causing the MIL somehow. Are the delivery/test mode…
Hi Justin, is there a PDI fuse installed in the fuse box? I recall this fuse was supposed to be removed when vehicle was delivered, I think the purpose is to keep the battery from draining during transport. Maybe someone installed this fuse again?
I can’t find a reference to a PDI fuse. the fuse box identification doesn’t show one in either the Underwood or underdash box. The PDI procedure lists installing a fuse for the interior lights room fuse.
Justin Have you try doing the DTC Display Mode to see if you can get any codes...
I have. The procedure doesn’t seem to work on this one.
Try an IPC self diagnostic and check DTC 1. Within 3 seconds after turning the ignition switch to ON, set the lighting switch to tail light or headlight position. 2. Press the odo/trip meter knob four times. 3. Turn the lighting switch to OFF, and press the odo/trip meter knob four times. 4. Set the lighting switch to tail light or headlight position again, and press the odo/trip meter knob…
That’s the procedure I tried. Nothing happens except the trip toggles between A, B and OD
Have you tried it three times? 1. Within 3 seconds after turning the ignition switch to ON, set the lighting switch to tail light or headlight position. 2. Press the odo/trip meter knob three times. 3. Turn the lighting switch to OFF, and press the odo/trip meter knob three times. 4.Set the lighting switch to tail light or headlight position again, and press the odo/trip meter…
Justin Have you try re-flashing the PCM i was talking to my vendor who rebuilds cluster they inform me there some kind of error in the ecm programming or the ecm its self, even if the pid showing it not to being command on it could still be... .. Might be something to rule out.... I remember you stated both cluster have the some issue i explain this to him and he didn't think it was a cluster…
Updated software just now. No change.
Justin Have you try reinstalling the original Cluster to the vehicle and try the DTC Display mode and see if it works.....there are two type of sequence and i believe you have the Normal Cluster
I skimmed through this quickly and I'm not at shop, so just throwing out some generic thoughts that crossed my mind, so I apologize in advance if someone covered it or anything comes across as insulting, which is not my intent. Did you try looking at build date and move up or down a year closer to the month of manufacturer for your schematics? I had a GM product that Vin was for a 2011, yet my…
Update the gry/red wire that had a 50%duty cycle would change with engine RPM. Cutting the wire cut the tach. So this leaves only CAN that is connecting the ECM and IPC.
My apologies, after re-reading your original post, I'm seeing what I missed. When you induced a CEL/MIL code, did the Cruise light flash along with the illumination of the CEL/MIL ? Any chance this vehicle had a used engine & harness installed ? I've seen oddities such as a CEL illumination without current / pending codes or symptoms on engine swaps, the differences being in the engine…
If you take the CAN network off of the IPC (eg remove the wires from the connector or cut them) does the light go out?
No. The light remains on with CAN wires removed from cluster connector.
2nd vid of cluster coolant sensor light didn't go out, is this only because of video being short? Also mileage is diff was this the second cluster or the same showing trip miles? Cause it seems the blue light went out appropriately in the 1st vid.
Mileage is different. They function the same. It’s just the timing of the videos that you see different.
How about going old school and try pulling the flash codes...? By the by: have fluid levels been verified? Gas cap? Maybe ecm self check will reveal what scanners have not...? Kind of time intensive but you could pull each sensor individually and verify corresponding fault registers by the ecm. Sounds like you have a lot of time invested in this one now.
Here's what I have for you so far: the c6/except c6 can be determined by the 6th vin digitdiag.net/file/f13zzsbm0… There also appears to be a delivery mode test connector. I'm not sure that has anything to do with it but I remember someone having a problem with a subaru that was caused by that being plugged in.diag.net/file/f1y1tokxi… If you unplug the ecm does…
Great info, Tanner! I have a Subaru of the same vintage with a wiring diagram that resembles the "Forester C6" one. The Subaru Service Manual for it has: - The Identification Section, with the MEANING OF V.I.N. on page marked ID-4. - Diagnostic steps for condition: MALFUNCTION INDICATOR LIGHT DOES NOT GO OFF. - Mentions that plugged in DELIVERY (TEST) MODE CONNECTOR causes the MIL to…
When the test connector is connected there is no change in mil function.
The green test connector is not connected. The wire for pin 33 on the B135 connector is non existent.
I think at this point we need an oem diagram to figure out what’s going on.
The diagrams in this post are oem from what I can tell. Try this one.
I had a random thought about the green connectors in the one photo above. Are those test connectors? Have you connected them together? On older Subaru's that would make the MIL flash and put it into some sort of diagnostic mode I believe. I am wondering if connecting them would get the MIL to flash. Maybe try clearing faults with the connectors together? Not sure that would change anything, just…
Hi, If you disconnect the ECM does the CE light go out?
No. The light remains with ECM unplugged
Unplug anymore modules one at a time till lite goes out...
The ECM part number has been superseded twice, from 22765AD400 to -AD401 to 22765AD402. [Genuine: - SKU:22765AD402 - Other Names:Unit EGI Control - Description: Forester. California. Manual trans. Without turbo. - Replaces:22765AD400, 22765AD401 subaruparts.com/oem-parts/suba…
This won't directly help you Justin, but for everyone following along, a quick check here; vinfreecheck.com/vin/JF2SHADC0C… shows this as a flood car / salvage title. After typing all that, it occurs to me, that could even be why the harness doesn't match the wiring diagram.
Looks like a Sandy vehicle, Geoff. Guido
The writing on the PCM is curious as well. Fiuza appears to be the name of a used car dealer in Utah not far from the town in Justin's profile. It doesn't strike as something that would be done at the factory.
We still need an oem diagram to confirm but after seeing that, my money is on the harness/pcm are not correct. Either harness isn’t correct for car or pcm is incorrect for car.
Looking at the wiring diagrams , the ECM talks to the BIU on the h/s can and the BIU reports to the I/C on low speed can . Using a scan tool on the BIU , there is a pid for the state of the C/E light. There are also settings in the BIU you can change , possibly someone has installed this from another car. HTH. You might be able to use bidirectional controls to operate it possibly.
I will have to look in data again. I didn’t see anything in data the first time under the BIU. I don’t recall seeing any bidirectional controls that were not basic body controls.
Update. I did finally get the cluster into diagnostic mode. All gauges and lights turn on and off. So the fact that the MIL turns off in one of the diagnostic modes leads me to believe the cluster can not be the issue. I did find a function to choose MT in the integ unit mode. It was set to AT. I changed it to MT. Still no change.
Have you tried replacing the PCM, don't remember reading about it?
No parts have been changed. I like to have good reason to call for a new part before changing parts.
Diagnostic Steps indicate a new ECM.
Looks like Geoff uncovered some clues as in potential flood damage. Have you taken a peak inside the ECM? That may provide you with the leverage needed to make such a call. Good luck, interesting issue.
I have looked inside the box. It looks pristine. Same goes for the BIU.
Currently this job is waiting for the customer to decide if they want to put anymore money into a flood vehicle. I will update if I get any resolution.