New member 2007 Liberty troubleshooting help.

[asw120]

Hi all, Jarrod here from Ipswich. I'm hoping for some assistance fixing my daughter's '07 Liberty with no accelerator.
Had some irrelevant codes on the odometer, borrowed a basic scan tool and got more codes. It has some codes relating to the accelerator pedal sensor, although this appears OK internally and is not open circuit anywhere (although I don't know the specs).
It also has a P0607 code, which worries me. Also, the check engine light does not work.
I have downloaded as US model manual, but it appears none of the wiring matches this car. In trying to see if the CEL should be on, the wiring diagram seems to direct me to an ECU pin with no wire in it? Same with the pin from the accelerator control relay (?).
I really don't want to put expensive parts into this car, unless I know it is the problem.

Any assistance anyone could offer (maybe I am interpreting the wiring diagrams wrong) would be greatly appreciated. There is a pile of things to fix, which have accumulated over time. I have a background in control circuitry, so I should be able to do this (although I am used to points and carbies).
After a good run from an early Forester, we have become a Subaru family. ('14 Forester eyesight wife's car, two older ones in the back yard.)

Best regards to all, Jarrod.

[Ric]

You don't mention which engine you have.
2.5 NA
2.5 Turbo
3.0 NA

[asw120]

You're right; it's a 2.5 N/A.

Jarrod.

[asw120]

I'm getting somewhere with this. When I switch the ignition on, I only get 0.1v at pin C1 at the ECU, this should go to 12v.
I need to find the throttle control relay. It appears to be behind the glovebox, from what I can find out. There are a few up on the front pillar, but I can't get to them. Having difficulty getting the glovebox out.
Does anyone know for certain if that's them and which is which?

Thanks.

[Ric]

The throttle relay is "B362" in the wiring diagram.
Here is the harness layout from the US service manual (LHD).
RHD models are probably a mirror image.

b362.png (105.9 KiB) Viewed 1709 times

wi-38.png (57.05 KiB) Viewed 1709 times

[asw120]

Thanks for that. After much searching I also found it.
There are additional issues, but I'm going to concentrate on this one first, since it has rendered the car undrivable.
I can see the relay, but the entire glovebox / end of the dash needs to come out. I have found the (vague) information on that and it's this weekend's job.

Cheers, Jarrod.

[bigBADbenny]

It might help to list all the DTC codes here, and also follow the DTC code specific diagnostic procedures you can find by searching the FSM.

Eg p0607 from memory is a failed ecu self test including the throttle pedal and plate correlation.

Since the fault might be the pedals sensor or the throttle body, following the specific procedures might be easier.

Also you’ll get more codes, Subaru specific on the odometer, than with a generic obdii tool, but list all here regardless.

Once you get all your codes, search the pdf FSM for the diagnostics… They’re intended to save time and guesswork.

[asw120]

Hi, I was not aware of that section of the manual, very helpful. I am going through it and will next go through the pages it references.
I can report that it was not the electronic throttle control relay and thus far, none of the pins on the ECU do what I expect. I am not sure if either of the two brown relays above it are the "main" relay, but swapped them with no effect.
Assuming that I am even testing the correct pins (and my .8mm mig wire backprobe with the laquer cleaned off is any good), I am getting no power to the throttle control circuit.
The FSM does give me a lot of specific things to try.
Codes are:
On Odometer: P0122, P2109, P0607, P 2127.
On scan tool: P0122, P2109, P0607, P2127, P2135, P0413 (cannot find this one in the manual, but it's the US manual)and then a repeat of: P0122, P0607, P2127 and P2135 in that order.
I wish I could get home a bit earlier after work, as this limits me to weekends (and on call this weekend).

I appreciate the info.
Thanks, Jarrod.

[bigBADbenny]

The point of using online resources is to avoid making assumptions generally.
You can do a resistance and voltage drop test on your mig wire probe to see if it’s affecting your readings for example.

The multimeter test strategy is outlined at the beginning pages of the wiring diagram section of the FSM, the diagnostics are arranged in a logical order, you can search the FSM for the pinout diagrams, and I’d recommend googling “the trainer” “voltage drop test” on YouTube as that test has interesting parallels to resistance testing.

Always look for the commonality between multiple DTC’s as that’s usually a clue to the core issue, or the multiple DTC’s cascade from a fundamental DTC.

Have you ever DIY cleaned the throttlebody?

[asw120]

Hi, no I have never done that.
So far, I have verified that my backprobe works. All the pins listed in the manual as being live all the time are dead and others are live that are not listed anywhere, leading me to wonder if the Australian wiring is radically different to the US wiring (which is all I have found available to date).
On familiar equipment, with the correct prints, I am pretty good at faultfinding.
I must confess, I have not tested every fuse, just the pertinent ones. Limited time is hampering progress, also.
I have tested power at what I believe to be the ETC relay and this makes sense, but does not tally with the pins on the ECU, which is confusing me.
Hoping to do the ohm tests as indicated this weekend, if I don't spend the whole time at work (on call).


Thanks, Jarrod.

[bigBADbenny]

See the red fsm link in my signature, there’s pdf & html fsm, some html fsm work on smartphones and or pc browsers.
Some fsm are general market, lhd &/or rhd, and also different languages!

HTML FSM use: works on smartphones…

https://jdmfsm.info/Auto/Japan/Subaru/L ... cy%202007/

Go to the DTC page, enter your code, click Go, choose the diagnostic link for H4SO (redacted) (your 2.5i…) and proceed to the diagnostics, save the wiring diagram pdf and screenshot each step. Each step also has links based on yes/no outcomes.

P0122:

STEP CHECK YES NO

1.CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM and electronic throttle control.
3) Measure the resistance between ECM and chassis ground.
Connector & terminal
(B137) No. 25 — Chassis ground:
(B137) No. 23 — Chassis ground:
(B137) No. 23 — (B136) No. 22:
Is the resistance 1 MΩ or more?


2.CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Connect the ECM.
2) Measure the resistance between electronic throttle control connector and engine ground.
Connector & terminal
(E78) No. 5 — Engine ground:
Is the resistance 1 MΩ or more?

Replace the electronic throttle control.
Repair the ground short circuit of harness between ECM and electronic throttle control connector. Replace the ECM if defective.


Repair the ground short circuit of harness between ECM and electronic throttle control connector.

[asw120]

Thanks for that. I have been looking there, trying to find a different wiring diagram.
Will have to keep looking.

Jarrod.

[asw120]

I got a bit further. I found a wiring diagram that matches. I also found the "EJ20" on the engine block, so it's a 2L.
It turns out the ECU is grounding the CEL/MIL wire. It's live disconnected, it's 0V connected, but light does not come on.
The ECU is not grounding the ETC relay. Even if I bridge the contacts, there is still no accelerator.
The manual with the correct wiring also has the P0413 code: SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE “A” CIRCUIT OPEN. It says to ohm the wires, but not how to test the valve. I have to find this out. The air pump and "cut air" relays test OK. The air pump appears seized, so I've unplugged it, as it draws a lot of current. I bridged the relay contacts and got a very warm jumper lead, but not a sound from the pump. I also bridged the cut air relay contacts and got a small spark, but no clicking, or anything.
I don't know if the P0413 is what's putting it in limp mode (and thus not commanding the ETC relay). Does anyone know if they will normally run OK with P0413 on?

Thanks.

[bigBADbenny]

The idea is you might review the multimeter test strategies at the start of the fsm wiring diagrams section then follow the the DTC diagnostics in order until you isolate the issue.

Always check you’re looking at diagnostics with the correct engine selected: H4SO for 2.5i, via the relevant links in an html FSM or FSM section (also listed at the lower end of each FSM page) with pdf FSM’s.

I posted the text from p0122 above but the fsm page has the related wiring diagrams and plug pinouts.
Then move onto the next DTC or look at the info from all the DTC’s to see the commonality.

This approach can be time consuming, if one had readily available spare parts you might “parts swap” eg starting with easiest first: the accelerator pedal assembly, then eg the throttle body.

Either way works best on your own time of course.

How the MIL light works/is tested is explained at the start of the FSM diagnostics section, but afaik, all DTC’s will force limp mode, I’ve not heard of any forcing the throttle to become inactive.

A secondary air valve being stuck open is not good, can create a fire in the engine bay from exhaust gasses burning the rubber air hoses apparently.

You can try spraying the valve from the air inlet hose side with carb and or upper engine cleaner, temporarily put the ecu into test mode (join one set of green plugs under the dash, for this procedure), and key on, engine not running, all solenoids, fans etc will cycle including the stuck air injection valve, the procedure: spraying & cycling, and maybe a gentle technical tap to help it shut.

My own car has a stuck shut valve, but I cheat the code by applying some throttle on key on: not a good idea for yours since you’re stuck open.

I really recommend just following all the procedures in order, and find someone parting a local my07-09 2.5i so you can get the required replacement parts.

If I get time I’ll post screenshots of all the DTC procedures via jdmfsm dot info, assuming you haven’t already done that?

[bigBADbenny]

So I got to the diagnostics for the four DTC’s, just to be sure: is the main car battery working properly?
Eg as it is, whats its voltage?
If you charge it completely on a battery charger what is the charged voltage, and then if left disconnected for 24h, to negate the “surface charge” what is the voltage then?

Otherwise, replace the battery after getting it load tested at a battery specialist vendor.

I’m not suggesting this as a cure-all, but it’s always a good first look on a new to you potentially neglected car.
One symptom is a flashing dash on key on start: indicates a “dropped cell” in the battery, as but one example.