Reduced engine performance

Post by **jonesg** » 22 Jun 2017, 09:37

2004 V70 Turbo, auto.

And engine service required warnings on the way to work today.

I drove to work and read the codes, heres what I got.
ECM 9530 Pedal position sensor signal too low.
ECM9540 Pedal sensor faulty signal

ECM 6220 ECU-BOX cooling fan signal missing.
I poked around that cooling fan, its not running, computers are hot. I unplugged it and get about 3.2v going to it.
The fan itself feels stiff, it does not freewheel when flicked with a screwdriver blade.

Is it possible the fan is knackered, computers are overheating and setting nutty codes?
Car drives quite normal.

Post by **jonesg** » 22 Jun 2017, 14:01

My voltmeter was set wrong, the computer cooling fan is not getting any power.
Does anyone know if theres a fuse somewhere for the cooling fan.

Post by **mrbrian200** » 22 Jun 2017, 15:39

Pedal position sensor has 1 or 2 sensor redundancies inside to prevent a failing pedal sensor from triggering unintended acceleration. If any one of them doesn't match the other(s) you will get this code and limp home/reduced power mode.
You will want to replace that fan ASAP. Sounds like the bearing got junk in it and wont turn.

Post by **jonesg** » 22 Jun 2017, 15:47

I don't get any voltage to the fan, swapped another in from the junkyard but it doesn't get power so it can't run.
Do they run continuously ?
Can I just give it a 12v feed?

I'm getting crazy codes all over the place after idling.
Both O2 sensors, heated seats, rear wiper motor,
is this related to the computer temperature.

I've checked every fuse I can find, no fuses blown.

Post by **jonesg** » 22 Jun 2017, 18:05

From reading it looks like there is no fuse for the ECM fan.
It gets constant 12v and the ECM switches it thermally by grounding the neg wire.
Doesn't sound right because I get no voltage at the plug to the ECMfan.
Can I feed it 12v voltage to cool it.
Not sure how to proceed here or if the codes it throws are real.

I just got VIDA but don't know how to use it properly yet. I've been reading codes with my Autel.

Post by **oragex** » 22 Jun 2017, 19:25

jonesg wrote: 22 Jun 2017, 15:47 I don't get any voltage to the fan, swapped another in from the junkyard but it doesn't get power so it can't run.
Do they run continuously ?
Can I just give it a 12v feed?

This fan only goes off when the two ECM modules are too warm - usually driving 10 minutes in summer weather. The fan must keep turning a little when kicked by hand. These commonly get harder to turn and needs replaced or the ECM modules will burn and cost more than the car to be replaced.

Post by **jonesg** » 23 Jun 2017, 14:25

oragex wrote: 22 Jun 2017, 19:25
jonesg wrote: 22 Jun 2017, 15:47 I don't get any voltage to the fan, swapped another in from the junkyard but it doesn't get power so it can't run.
Do they run continuously ?
Can I just give it a 12v feed?
This fan only goes off when the two ECM modules are too warm - usually driving 10 minutes in summer weather. The fan must keep turning a little when kicked by hand. These commonly get harder to turn and needs replaced or the ECM modules will burn and cost more than the car to be replaced.

I jumped the fan and it ran fine, got one from the junkyard and that ran the same when jumped with 12v.
Then I ran the engine and the fan never cycled on, computers felt very warm.
My plan is to just feed it 12v , I'll be stuck with a fan code but at least the computer won't fry.
UNless you have a better idea.

Post by **jonesg** » 24 Jun 2017, 00:02

I believe the problem is solved.
Someone told me the ebox fan is fuse #8 but that probably isn't the trouble because there are other things on that fuse which would cause trouble.
Looked it up in the owners manual , "Fuse #8 accelerator pedal position sensor, E-box fan."

But I am getting a throttle position sensor code ( 3 of them actually).
Car is at work but I'm confident this will be the root of it all.

Post by **abscate** » 24 Jun 2017, 04:16

jonesg wrote: 24 Jun 2017, 00:02 I believe the problem is solved.
Someone told me the ebox fan is fuse #8 but that probably isn't the trouble because there are other things on that fuse which would cause trouble.
Looked it up in the owners manual , "Fuse #8 accelerator pedal position sensor, E-box fan."

But I am getting a throttle position sensor code ( 3 of them actually).
Car is at work but I'm confident this will be the root of it all.

That certainly would fit all the symptoms!!

Post by **mrbrian200** » 24 Jun 2017, 09:43

This circuit also provides +12v for the A/C compressor relay and the compressor clutch itself. If the fuse is bad and you replace it/ gets pulled out again something in this circuit is the likely culprit. If the codes keep coming up but the fuse is fine the diode across the clutch winding has likely gone bad which results in a voltage spikes on this circuit when the compressor cycles on/ off. If the diode or clutch winding is intermittently shorting/arcing (but not long enough to pull the fuse out as it's not a fast acting type) the voltage in this circuit may be pulled down momentarily. In which case it sounds like the ECU is interpreting this as a problem with the attached devices (Pedal sensor, ecu fan).