1999 xc70 ETS light, limp, codes Dodgertom troubleshooting

[Dodgertom]

more info. got my code reader resurrected long enough to pull codes again.

prior 3 codes still there.

clarify one of those:

604D, not 6040, so some tex-message info code

3 new codes:

917f
9520
958f

all having to do with the accelerator pedal position sensor.

went through exemodec's diagnostic tree, and

turned on the ignition, not started
hear a whine coming from throttle body
pulled #2 fuse
whine ceases
replaced #2 fuse
tb clicks and whines for about 6-7 seconds
clicks again and whine ceases

that seems to indicate that the throttle body is okay.

is it?

thanks in advance.

[Dodgertom]

unless the accelerator pedal position sensor is in the throttle body, right?

[scot850]

Those are the 2 sensors that fail in the throttle bodies and Xemodex replaces. Basically the sensors are a needle and a carbon pad that adjusts the throttle position as you press for more gas. Over time the needle wears through the carbon giving incorrect info. What Xemodex does is replaces that old tech with new contactless sensors to eliminate that issue.

What you are testing with the fault tree is that the ETM itself is not completely dead, but it is able to start and try to zero position itself. Doesn't mean it is working correctly. I would expect it to throw a code though if it was not sensing correctly.

Neil.

[Dodgertom]

thanks, neil.

[scot850]

I may have an ETM from a 99 V70XC. No idea if it is good or bad as it came from a junkyard and have no way of testing it to know if it is good or not. I will check later what I have as I may have more than one for an LPT motor.

Neil.

[abscate]

Those codes point to the 7/51 accelerator pedal position sensor but that’s a very rare to fail item. The 7/51 shares a common 12V feed ( green white wire ) with the ETM so it’s worth a check there. See diagrams from VIDA below

I think it’s likely your ETM is generating spurious codes on the accelerator pedal, that has been seen before here.

Accelerator pedal sensor part number 30683511 nasty expensive , like $300

Updated ETM contact less part number 36050563

[Dodgertom]

thanks, steve.

shifting my focus to getting the bus going so i have at least one running vehicle.

joshua at xemodex thinks it’s the ecm cause of the no-response to the key symptom. it has occurred to me that it might have stalled in drive, which i think would explain that. i really don’t remember, but that makes sense.

your feedback on the tcm throwing pedal-sensor codes is helpful. plan on getting a tcm next week when i also hope to get my new radiator. might as well do both at once.

i appreciate your and neil’s help.

will comment when i do the swap.

[scot850]

These guys have rebuilt ETM's for $450 of which $150 is a refundable core charge:

https://www.swedishcarparts.com/parts/1 ... to-install

I also checked my stash, I have 3 x ETM's from 99-00 V70XC's. No idea how or why I bought these, but hated to see them getting crushed!

So they are all from 4 speed auto's (no manuals were sold in NA that I am aware).

Whatever you do, I hope it gets fixed!

Neil.

[Dodgertom]

well, i got the bus going (about which i ‘ll post in the samba), so time to turn back to the v70 xc. in the interim the battery died. considering the feedback from joshua at xemodex and neil here, i thought, hey, maybe that’s it!

replaced the battery. no ets light. started moving forward. no limp mode. good, at first, but, then, as i accelerated, there’s this noise like something rubbing. car started surging radically in both drive and reverse. the surging seems to have abated with some short test drives, but, when i hit the gas there is a definite whirring sound.

the only error code (no check engine light) is 6806, turbo control system, too high or low flow.

[scot850]

Can you narrow the rubbing sound to an area of the car? It is unlikely to be caused by the ETS. The surging however may be.

The rubbing sounds I have had over the AWD P80 years are:

1) Brake dust shield bent and rubbing - however, if you have not had the wheel off recently then that is less likely.
2) Sticking brake caliper - depending where the noise is coming from could be front or rear caliper.
3) Wheel bearings - identified by turning left or right will get louder on left side when turning right and vice versa.
4) CV boot on any of the axles split. More likely the fronts
5) RH front axle carrier bearing failing
6) Front propshaft bearing, center support bearing failing/broken
7) Front viscous coupling bearing failing - again I noticed it most when turning I got a rubbing sound from towards the back of the car.
Parking brake shoes failed (shoe material delaminated from metal shoe) or parking brake cable seized.

Code 6806 - This thread talks a lot about Vida, but also may help you figure this out. Would appear to point to an air/vacuum leak:

viewtopic.php?t=96742#:~:text=ECM%2D680 ... 0too%20low

Neil.