2000 V70 starting mystery

CaptainJoe75 · Post by **CaptainJoe75** » 02 Jun 2018, 08:55

Good morning all (or good day, wherever you may be),
This is my first post here, though I have been lurking and reading for months.

I have a 2000 V70XC 2.4T (240k) that has me stumped and more than a little frustrated.

Initially it displayed the classic ETM failure symptoms three weeks after I bought it. I replaced the ETM with a boneyard unit (yellow sticker) and it was fine for another three weeks, at which time I bought a unit from XemodeX.

After installation, no change. The car would try to start, firing for a few seconds at a time and dying.

Codes: P0118, P0237
Replaced the coolant temp sensor and the boost pressure sensor.
No change, but codes are gone.

Replaced MAF with brand new unit, no change.

Tested fuel pump and found intermittent operation and low pressure...replaced fuel pump with brand new unit.

Now the car will fire for a second or two at a time and die unless I hold about 30% throttle.
This will allow the engine to stay running but RPM surges from about 500 to about 2000 and the tachometer is not working, ETS light is on and it will die after 20-30 seconds.

Perhaps these symptoms will be familiar to someone here...
Thank you in advance for any input.

Post by **FLXC90** » 02 Jun 2018, 12:25

First off welcome to MVS!

Can you contact the previous owner? Had they already replaced a faulty ETM with another from a junkyard before selling it to you? Did you actually purchase current ETM from Xemodex, using VIN verification of part number etc... Have you contacted Xemodex customer service? Do you have/have access to DICE/VIDA?

CaptainJoe75 · Post by **CaptainJoe75** » 02 Jun 2018, 13:22

Thanks for the welcome,

PO is unresponsive, all I know is that it had a yellow sticker unit, which I replaced with a yellow sticker used unit. When the car quit again I bought a "new" (re-man?) from XemodeX (pre-programmed to my VIN)
XemodeX technician says he is unsure but it sounds like ECU...I am unconvinced of this.

I only have access to a standard cheap code reader.

Additionally, I can hear the fuel pump surging almost in time with the engine.
I will try to post a video...

Post by **RickHaleParker** » 02 Jun 2018, 13:23

Both of these defects can mess with your Air/Fuel ratio. Correcting both should solve the problem.
Check the wiring first.

-----------------------

ECM-2000 (P0018) Engine coolant temperature (ECT) sensor. Signal to high, Signal to low, Intermittent fault
Print

Diagnostic trouble code (DTC) information

Condition
If the control module receives a signal from the engine temperature sensor corresponding to a temperature lower than -47°C (-52.6°F) or higher than +143°C (289.4°F) the control module interprets it as a fault and ECM-2000 is stored. As soon as the engine is started the temperature is calculated theoretically. If the calculated temperature exceeds the engine coolant temperature (ECT) sensor signal, the control module interprets as a fault and ECM-2000 is stored.

Substitute value
a calculated engine temperature is used, intake air temperature is used as base value
engine cooling fan (FC) runs at low-speed

Possible source
Signal too high:

short-circuit to ground in the signal cable
defective temperature sensor

Signal too low:

open-circuit in the signal cable
short-circuit to supply voltage in the signal cable
defective temperature sensor
contact resistance in terminals

Faulty signal:

defective temperature sensor
faulty engine coolant thermostat

Fault symptoms
Malfunction indicator lamp (MIL) lit

-------------------------------------

ECM-1600 (P0237) Boost pressure sensor. Signal too high, Signal too low, Permanent fault

Diagnostic trouble code (DTC) information

Condition
If the control module receives a signal from the boost pressure sensor which is lower than 0.2 V (low signal) or higher than 4.85 V (high signal) it is interpreted as a fault and ECM-1600 is stored.

Substitute value
Boost pressure control runs in an open-loop, in other words set duty cycles are generated regardless of boost pressure.

Possible source
Signal too high:

contact resistance in terminals
short-circuit to supply voltage in the signal cable
open-circuit in signal cable
defective boost pressure sensor

Signal too low:

short-circuit to ground in the signal cable
defective boost pressure sensor

Fault symptoms
none

CaptainJoe75 · Post by **CaptainJoe75** » 02 Jun 2018, 13:59

Well, now it won't start like it was.
Just the fire and stumble.
Does that fuel pump sound right?[youtube][/youtube]

Post by **FlyingVolvo** » 02 Jun 2018, 15:09

Have you measured fuel pressure at the rail? The fuel pump relays are known to go bad (replace with OEM, not KAE brand). Can't really hear the fuel pump when cranking, but do you hear it prime (from under passenger rear seat) when go you from key position I to II?

Did you use OEM Volvo for the coolant temp sensor as well? Aftermarket shouldn't be used there either.

I would also doubt the ECU. Hard to find anyone who's actually had one go bad.

Edit: Yeah, I take that back. As rspi pointed out, that is weird about the mileage readings all being dashed out.

Threads involving my exact year/model like this always pique my interest!

Post by **scot850** » 02 Jun 2018, 15:10

What brand of fuel pump did you use? We recently had a post here about a batch of aftermarket pumps that were bad. They had the wrong mesh filter over the pump (they were for E85 fuel) and would not work for the owner.

I notice that when you try to start the car all the dash outputs are at '-----'. This can be caused by a few different issues and may not be related to your current problem.

1) Do you know if the electrical portion of the ignition switch has been replaced?
2) Do you have 2 keys for the car? Being a 00 it has a chipped key that is read by an antenna ring around the ignition key. If this is damaged of the key chip has failed it will not start.
3) Did you replace the fuel pump relay?
4) All the dash errors are likely to be the ABS module has failed. Speak to Matty at Mid-West ABS for a replacement re-built unit on exchange.

Neil.

Post by **rspi** » 03 Jun 2018, 19:30

There is a chance that the ECU is bad. Had a serious starting issue on a '00 S70, replaced the ECU with one from the junkyard (software swapped by XoMODex).

There is some serious issue, you have no mileage showing in the cluster. I'd have a Volvo mechanic check it out.

Post by **800artfreed** » 10 Sep 2022, 14:00

Any solution to this problem? It would be a great help to the rest of the community. Thanks.