2017 XC60 D5 AWD - Zero Boost Before 3000RPM

[jronnquist]

Anyone have any experience with this issue?

The dreaded (and completely meaningless) "Engine System Service Required" message has been living on my dash for the last few days now and the only observable symptom is a complete loss of boost until you hit 3000RPM. It's basically a tractor until 3K, at which point it takes off like a rocket. Reminds me a bit of the Mk1 Evo.

The engine is the two-stage turbo D5244T11, which leads me to conclude that little brother has gone on strike. I will of course be taking the car in for a code read, but wanted to see if anyone else has experienced this issue as I've tried about a million different ways of expressing the problem in Google and can't find a single result that comes even close. I know there's a way to get engine fault codes out of the old analogue dash, but I've got the LCD one, so no luck there.

I guess what I'm trying to establish is whether it's more likely that I've got a dead turbo or that the ECU is just holding it in check for some reason.

Any tips would be great. I will of course add more information (and hopefully a solution) as things develop.

[Clan]

Originally Posted by jronnquist

Anyone have any experience with this issue?

The dreaded (and completely meaningless) "Engine System Service Required" message has been living on my dash for the last few days now and the only observable symptom is a complete loss of boost until you hit 3000RPM. It's basically a tractor until 3K, at which point it takes off like a rocket. Reminds me a bit of the Mk1 Evo.

The engine is the two-stage turbo D5244T11, which leads me to conclude that little brother has gone on strike. I will of course be taking the car in for a code read, but wanted to see if anyone else has experienced this issue as I've tried about a million different ways of expressing the problem in Google and can't find a single result that comes even close. I know there's a way to get engine fault codes out of the old analogue dash, but I've got the LCD one, so no luck there.

I guess what I'm trying to establish is whether it's more likely that I've got a dead turbo or that the ECU is just holding it in check for some reason.

Any tips would be great. I will of course add more information (and hopefully a solution) as things develop.

No harm in taking the inlet pipe off the little turbocharger at the top and wiggling the turbine wheel inside , a tiny amount of up/down play is how its designed ..but no in/out play ... you could find it seized or broken or wiggling around but that's very uncommon .

[jronnquist]

So this is what the code reader has to say:

Code 1: Volvo DTC ECM-P023600

Turbo/Super Charger Boost Sensor "A" Circuit Range/Performance

The Engine control module (ECM) regulates the turbo pressure using a turbo control valve. The control module has integrated functions to check the function of the turbo control valve. The diagnostic trouble code (DTC) is stored if the control module detects that: The turbo pressure is too high, compared with the internal calculating models in the control model. The difference between the atmospheric pressure and the pressure in the intake manifold (before the throttle unit) at idle is greater than a value that can be calibrated. The difference in pressure before and after the throttle module, during large throttle openings, is greater than a value that can be calibrated. The control module's test for the diagnostic trouble code (DTC) starts in the event of: Normal load (driving). Intake pressure is greater than atmospheric pressure. Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met

Causes:

1. Damaged atmospheric pressure sensor.
2. Damaged boost pressure sensor.
3. Damaged air pressure sensor in the inlet manifold.

Code 2: Volvo DTC ECM-P029900

The Engine control module (ECM) regulates the turbo pressure using a turbo control valve. The control module can detect small faults in boost pressure regulation over a longer period of time and larger faults in a shorter time. The diagnostic trouble code (DTC) is stored if the control module detects that: The actual turbo pressure is less (approx. 15 kPa for 10 seconds) than what the Engine control module (ECM) regulated (maximum regulation achieved). The control module's test for the diagnostic trouble code (DTC) starts in the event of: Normal load (driving). Boost pressure (approx. 30 kPa above atmospheric pressure). Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.

Causes:

1. Damaged turbocharger (TC) control valve.
2. Air leakage in the intake system.
3. Damaged turbo charger (TC).
4. Damaged relief valve.
5. Hoses between the pressure servo for the boost pressure control (BPC) valve and the turbocharger (TC) control valve have come loose or are blocked or damaged.
6. Sticking boost pressure control (BPC) valve.
7. Damaged boost pressure control (BPC) valve pressure servo.

There are clearly quite a few things that can cause the issue, so need a diagnostic plan. So this is what I have come up with:

1. Full inspection of all air intake/boost pipes and intercooler for leaks.
2. Check that the vacuum actuator that switches between the 2 turbos is working.
3. Fuel filter change.
4. Replace MAF and intake manifold pressure sensors (and atmospheric pressure sensor, wherever the hell that is).
5. Replace turbo or get rid of the car depending on cost.

Will keep updating as I go.

[Clan]

Originally Posted by jronnquist

So this is what the code reader has to say:

Code 1: Volvo DTC ECM-P023600

Turbo/Super Charger Boost Sensor "A" Circuit Range/Performance

The Engine control module (ECM) regulates the turbo pressure using a turbo control valve. The control module has integrated functions to check the function of the turbo control valve. The diagnostic trouble code (DTC) is stored if the control module detects that: The turbo pressure is too high, compared with the internal calculating models in the control model. The difference between the atmospheric pressure and the pressure in the intake manifold (before the throttle unit) at idle is greater than a value that can be calibrated. The difference in pressure before and after the throttle module, during large throttle openings, is greater than a value that can be calibrated. The control module's test for the diagnostic trouble code (DTC) starts in the event of: Normal load (driving). Intake pressure is greater than atmospheric pressure. Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met

Causes:

1. Damaged atmospheric pressure sensor.
2. Damaged boost pressure sensor.
3. Damaged air pressure sensor in the inlet manifold.

Code 2: Volvo DTC ECM-P029900

The Engine control module (ECM) regulates the turbo pressure using a turbo control valve. The control module can detect small faults in boost pressure regulation over a longer period of time and larger faults in a shorter time. The diagnostic trouble code (DTC) is stored if the control module detects that: The actual turbo pressure is less (approx. 15 kPa for 10 seconds) than what the Engine control module (ECM) regulated (maximum regulation achieved). The control module's test for the diagnostic trouble code (DTC) starts in the event of: Normal load (driving). Boost pressure (approx. 30 kPa above atmospheric pressure). Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.

Causes:

1. Damaged turbocharger (TC) control valve.
2. Air leakage in the intake system.
3. Damaged turbo charger (TC).
4. Damaged relief valve.
5. Hoses between the pressure servo for the boost pressure control (BPC) valve and the turbocharger (TC) control valve have come loose or are blocked or damaged.
6. Sticking boost pressure control (BPC) valve.
7. Damaged boost pressure control (BPC) valve pressure servo.

There are clearly quite a few things that can cause the issue, so need a diagnostic plan. So this is what I have come up with:

1. Full inspection of all air intake/boost pipes and intercooler for leaks.
2. Check that the vacuum actuator that switches between the 2 turbos is working.
3. Fuel filter change.
4. Replace MAF and intake manifold pressure sensors (and atmospheric pressure sensor, wherever the hell that is).
5. Replace turbo or get rid of the car depending on cost.

Will keep updating as I go.

I would do the above red items , mainly the one in the intercooler outlet pipe below the left hand headlamp.
These have been causing problems on some volvos for the last 5 years , previous to that very reliable ...

[jronnquist]

Originally Posted by Clan

I would do the above red items , mainly the one in the intercooler outlet pipe below the left hand headlamp.
These have been causing problems on some volvos for the last 5 years , previous to that very reliable ...

Thank you for your original reply and this advice. I never actually got around to the sensors as I ran into the source of the problem about 5 minutes into my diagnostic checklist. See below.

[jronnquist]

I originally thought this was the actuator for the larger of the two turbos, but learned from a YouTube video this morning that it is in fact the actuator for the flap that diverts the exhaust to one or other of the turbos depending on what the ECU requires. Furthermore, it's default position (no vacuum pressure) sends everything to the larger turbo. You couldn't see the split as it was on the back of the hose, but I gave it a little tug and off it fell. So I cut the split end off, pushed it back on and, presto, I now have two turbos again! Just need to replace it with a fresh hose of the correct length as it is now a little short.

[Clan]

Originally Posted by jronnquist

I originally thought this was the actuator for the larger of the two turbos, but learned from a YouTube video this morning that it is in fact the actuator for the flap that diverts the exhaust to one or other of the turbos depending on what the ECU requires. Furthermore, it's default position (no vacuum pressure) sends everything to the larger turbo. You couldn't see the split as it was on the back of the hose, but I gave it a little tug and off it fell. So I cut the split end off, pushed it back on and, presto, I now have two turbos again! Just need to replace it with a fresh hose of the correct length as it is now a little short.

most unusual , someone has damaged that doing previous work ...

[jronnquist]

Originally Posted by Clan

most unusual , someone has damaged that doing previous work ...

That would not surprise me in the least.

This car went back to the dealership 2 months after I bought it to replace a leaking radiator (a well known issue with this model and year, I believe). The garage that did the work managed to break 2 wire mounting points and did not reconnect the A/C compressor.