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P0600, Limp mode, ER HC, ER SS

5212 Views 69 Replies 10 Participants Last post by  AnotherSubaruGuy
2008 Outback 2.5i Limited w/ VDC. When I put the car into drive it moves forward but when I press the gas it just revs, it will accelerate under its own power and allow some throttle response once moving but if I give it too much gas it just revs higher. This is especially problematic when making a sharp turn, causing the car to be undrivable on public roads.

Background on the car: The guy I bought the car from said it needed a transmission. I found it had the WRONG transmission in it (one without VDC, code TZ1B8LFEBA) so I replaced it with the proper transmission (with VDC, code TV1B8MFEBA) and got 1,500 miles out of the replacement. I was driving, made a turn, the car revved without acceleration for a few seconds and slammed super hard into gear and threw all the dash lights. I limped back down the highway about 3 miles to my shop and that was that. Scanned and had a code for a pressure control solenoid (can't remember exact code) and decided to just replace the trans again.

I installed the next used replacement, and the first drive seemed like a big improvement until it got up to full temp and started doing the things mentioned in the first paragraph. Last time I scanned it I had codes C0045, C0022, C0052, no Pxxxx codes stored in the ECM or TCM. I figured there's no way this thing is just spitting out trannys so I replaced the TCM and it's still not fixed. Fluid level looks good and no noticeable faults in the wiring. Where else do I look or how do I go about about testing things? Any input is appreciated.
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Some observations, comments, . . .

In park the wheels were spinning, can't recall if that's normal, . . .
All four? When in Park, the front wheels should not be turning. The parking pawl in the tail section engages a gear tand pinion shaft connected to the front differential. The pawl prevents the gear from turning, and therefore the front drive from turning. Are you sure this was in Park?

. . . in drive . . . it seemed to be letting the power go to the wheels as I revved the engine like it should be when all 4 wheels are in the ground
Very little torque is required to turn the wheels when they're raised. This doesn't simulate the conditions when the car is on the ground and a lot more torque is needed to move the car.

. . . when I pressed the brake the ABS kicked in . . .
To be expected. When the pedal is pressed with the car raised, one wheel could stop while the others continue to turn. To the ABS, that's a skidding wheel and so the ABS kicks in to control the "skid".

When the car is being driven, and the accelerator pedal is pressed down, engine torque is increased, and there should be a corresponding acceleration of the car. If the engine revs up, without any corresponding acceleration, there is some sort of "disconnect" between the engine output and the wheels. This could be in the engine/torque converter connection, the torque converter, the transmission gear set, or the drive train to the front or rear wheels (drive shafts, differentials, axles). The converter and transmission are less likely if two transmissions with their own torque converters were installed properly and the car is exhibiting identical symptoms. All the more so if the car had the exact same symptoms when first purchased, before changing the tranny. That essentially leaves the drive trains to the front and rear wheels.

There have been cases of a CV joint in an axle failing, but not falling apart. Visually it looks fine. Moreover, if one twists the two ends of the axle by hand, it might seem intact because of residual friction in the joint. But when that twisting involves higher torque, the joint begins to slip, and torque transfer is lost. The part that is connected to the differential spins freely, and that reduces the torque available to other wheels. The engine revs but the car doesn't accelerate. Similar symptoms could be experienced if an axle has pulled out of the differential. A movement of about 1/4" is enough to disengage the splines on the axle from the splines in the differential side gear. The axle appears to be in place (not hanging down), but it's not connected inside. I'm not saying these are your problem, but the symptoms would be similar to what you experienced, especially most recently when you "gave it some good gas on our gravel driveway. . . "
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C0045 has two source possibilities, according to the attached diagnostic tree. In both cases the symptoms are ABS/VDC not operating.

TC adjusts engine torque to conditions (e.g., slip/slide) by limiting engine fuel and/or throttle. Your reports say that the engine revs when the accelerator is pressed, which doesn't seem to suggest TC coming into play.


Do you have the 2008 factory service manual?

In the manual, the diagram you posted above applies only to models with VDC. I checked the FSMs from 2005 to 2009 and they are all the same. (Similar diagrams for cars without VDC show the traditional locations.) The location of the ECM and TCM in the VDC cases are, indeed, different for Subaru, but it would be equally odd for the FSMs over five years to remain grossly in error. Have you found your 2008 VDC's ECM and TCM?

The FSM "Wiring System" section has pages mapping out the ground system. It will show the VDC module pin 25, and where that goes, typically through a wiring harness to an identified ground point, along with any intervening connectors shown as well. Also, toward the end of the Wiring System section there's diagrams of each of wiring harness. The wiring harness diagram will show where they attach to body or other ground points.

Also, the VDC unit has two grounds. One is from pin 25, but there's another at pin 22. The latter goes to a ground lug on the chassis rail below the VDC module.

Are you sure your 5 Ohm measurement is at pin 25? Very easy to mistake the location of a pin when using the diagrams in the FSM and comparing to actual connector. Wire color can help confirm if it's the right pin.

Is your meter reading resistance correctly? Have you checked other grounds, or between the battery negative and some other point on the car body to see what it reads there?
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That's really puzzling about those VDC diagrams in the FSM, but I accept that they don't apply to your VDC.

is my best bet just following wiring as deep as possible? I'm losing the harness under the dash where it goes behind the HVAC and stereo head unit.
That might be one point to look for.

Here's the relevant page of the VDC wiring diagram. It shows that the connection from pin 25 is a continuous wire to a ground connection shown on page 3 of the Ground Circuit of the wiring diagrams section (page GND-03).

Rectangle Font Parallel Slope Schematic

Next is page GND-03. I marked the connection from pin 25 to a ground connection identified as GB-7 and to ground GB-5. Also, note that the pin 25 ground wire goes off on the right to "G" on page 4 of the Ground Circuit. On page 4, "G" is connected to two more ground points, GB-8 and GB-9. Also, the same wiring goes off the right to "J" on page 5, and on Page 5 it, once again, connects through to another ground, GB-11. The ground connection from pin 25 to GB-7 and GB-5 has no connectors, but the continuing ground wiring to GB-8, GB-9 and GB-11 does involve connectors. (I have not copied these other pages; they're all continuous in the FSM.)

Product Rectangle Font Slope Line

Pin 25 is identified as a pin in connector B310. The "B" identifies the harness, in this case, the "Bulkhead Wiring Harness". This harness is found in the engine compartment area and in the cabin. Toward the end of the FSM Wiring System section, there's more detailed layout of each harness in the car. There's two for the Bulkhead Wiring harness; one for the section in the engine area, and the other for part (of the same harness) that is in the cabin. Here's the cabin one that shows the location of the GB-7 ground (highlighted) and slightly to the left of that, GB-5, both under the dash on the right side.

Organism Font Rectangle Parallel Slope

There's quite a number of other electrical components that make use of the same GB-7 and GB-9 grounds, including, on page 1 of the Ground Circuit, the vanity lights in the mirrors of the sun visors, and the ceiling light and map lights when they are manually switched on.
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