It might be the thermostat giving incorrect readings. If the coolant is up to level and the pump and fan is running I would guess its the thermostat. It may be stuck in the closed position.
2018 XC90 OVERHEATING
Car overheating. Have replaced water pump and oil cooler seal to no avail. Cooling system also been bled out, no luck. Thermostat getting replaced next. Anyone experienced anything like this? What else can it be? Car has 64k miles. TIA
1 - 13 of 13 Posts
Flow restriction (contaminant buildup or kinked line, for example) can lead to reduced heat transfer to cooling fluid and thus an overheated engine. The condition of the cooling fluid during the bleed out (dirty with contaminants, best case) may or may not be an indicator.
Does the thermostat give readings?It might be the thermostat giving incorrect readings.
Does the radiator cooling fan turn on? Turn on AC and see if the radiator fan turns on.
Probably the thermostat. What code(s) is it showing?
Thanks all for the feedback. Coming back to report that the thermostat was replaced, drove it around town, and 2 days later (today) it overheated again! Going back to the shop - problem seems to be bigger than I thought.
I forgot to ask them for the code. However the thermostat was replaced and overheated 2 days laterProbably the thermostat. What code(s) is it showing?
Flow restriction (contaminant buildup or kinked line, for example) can lead to reduced heat transfer to cooling fluid and thus an overheated engine. The condition of the cooling fluid during the bleed out (dirty with contaminants, best case) may or may not be an indicator.
I forgot to ask for the thermostat readings but shop told me it was not opening, so they replaced it. Drove it for 2 days after replacing it and overheated again today! The overheating is intermittent which is the weird thing - the message disappears within just a few minutes, sometimes within seconds after it alerts meIt might be the thermostat giving incorrect readings. If the coolant is up to level and the pump and fan is running I would guess its the thermostat. It may be stuck in the closed position.
to “reduce speed” or “pull over and stop”. The fans blow like crazy during that time and eventually cools things down. No coolant leaking - coolant expansion tank not bubbling over. Not sure 🤔
Fan is working when AC is on and immediately kicks on when the “overheating” message comes onDoes the radiator cooling fan turn on? Turn on AC and see if the radiator fan turns on.
Is this a Volvo tech working on your XC90?Fan is working when AC is on and immediately kicks on when the “overheating” message comes on
OBDII tool to monitor temps as you drive. Maybe it is the actual temp sensor reading high.
If you start it cold in the morning, and it reads higher than ambient, there you go.
If you start it cold in the morning, and it reads higher than ambient, there you go.
The original coolant temp sensor in the T-stat can short out, set ECM-PO171 code that will not clear. If this happens, the t-stat circuit in the ECM has shorted out. The ECM will need to be replaced. The ECM warranty is 8/80.
Volvo may have extended the ECM warranty for this code; I could not locate that information. Xemodex.com and repair your ECM for this code. If your ECM does have the permanent P0171 code, I do not know if this would keep the cooling fan from not turning on or not or register a correct engine temp. As mentioned, use an OBD reader to check for engine temperature. Below information is from Xemodex.com web site about this.
ENGINE CONTROL MODULE FOR VOLVO VEA ENGINES
Repair Service
XeMODeX Price: $329.00
Engine Control Module for Volvo VEA Engines quantity
Add to cart
Application
▼
All Volvos fitted with the 2.0L 4 Cylinder VEA Engine
▼
What you need to know (please read before ordering)
▼
Important: This is a fault specific ECM repair service that addresses the following Thermostat Heater Circuit failures:
• ECM-P059700
• ECM-P059800
• ECM-P05990
• P0597
• P0171 “Thermostat Heater Control Circuit”
• New Thermostat heater is installed and codes still won’t clear
If you have any other issues, please contact us prior to purchasing this service.
This is a Repair service service of your existing module. You will need to remove and send your module to us for repair using the shipping labels provided to you.
The order will be processed during our regular business hours (Mon-Fri 8:30 – 5:00 EST). After processing your order, we will email shipping labels and shipping instructions. If you don’t see shipping labels within 1 hour of submitting your order (during business hours) please first check your junk/spam folders. If you still don’t see the labels, please contact us at 1-888-712-2525
Features:
Plug & Play: The software and settings will not be modified, making this module plug and play. No software reload or calibration is required after installation.
Quick Turnaround: Your module will be tested, repaired, tested again, and sent back to you in the same day (unless otherwise noted).
Quality Tested: All our Volvo ECMs undergo rigorous tests on our specialized custom built CAN-bus driven test bed. Functions, DTCs, and software are checked and verified for proper operation.*
Please note that since this is an Engine Control Module some functions can only be tested when installed in the vehicle with a working engine, meaning testing is limited outside of the vehicle. If you’re in doubt of whether or not your ECM is faulty, please consult with a Volvo specialist or contact our tech support by submitting a Technical Question Form here.
Reference Numbers
▼
Common Failure Symptoms
▼
Root Failure Cause: Shorted thermostat heater causes internal damage in the ECM, resulting in:
• ECM-P059700
• ECM-P059800
• ECM-P05990
• P0597
• P0171 “Thermostat Heater Control Circuit”
• New Thermostat heater is installed and codes still won’t clear
Volvo may have extended the ECM warranty for this code; I could not locate that information. Xemodex.com and repair your ECM for this code. If your ECM does have the permanent P0171 code, I do not know if this would keep the cooling fan from not turning on or not or register a correct engine temp. As mentioned, use an OBD reader to check for engine temperature. Below information is from Xemodex.com web site about this.
ENGINE CONTROL MODULE FOR VOLVO VEA ENGINES
Repair Service
| MSRP: | $1,070 (Save 70%) |
| Shipping: | $79 Express $39 Ground |
| Services Type | Repair Service |
| Turnaround Time: | Same Day |
| OEM Part Number: | 36011422 |
| XeMODeX Part Number: | VO.1050.ECMVEA.10.20 |
| Reload Required? | No. Plug and Play Installation |
| Warranty: | Lifetime Limited Warranty |
Engine Control Module for Volvo VEA Engines quantity
Add to cart
Application
▼
All Volvos fitted with the 2.0L 4 Cylinder VEA Engine
| 2014 – 2019 | Volvo | S60 |
| 2015 – 2016 | Volvo | S80 |
| 2017 – 2017 | Volvo | S90 |
| 2014 – 2019 | Volvo | V60 |
| 2015 – 2019 | Volvo | V60 XC |
| 2017 – 2019 | Volvo | V90 |
| 2017 – 2019 | Volvo | V90 XC |
| 2018 – 2019 | Volvo | XC40 |
| 2014 – 2019 | Volvo | XC60 |
| 2014 – 2016 | Volvo | XC70 |
| 2015 – 2019 | Volvo | XC90 |
▼
What you need to know (please read before ordering)
▼
Important: This is a fault specific ECM repair service that addresses the following Thermostat Heater Circuit failures:
• ECM-P059700
• ECM-P059800
• ECM-P05990
• P0597
• P0171 “Thermostat Heater Control Circuit”
• New Thermostat heater is installed and codes still won’t clear
If you have any other issues, please contact us prior to purchasing this service.
This is a Repair service service of your existing module. You will need to remove and send your module to us for repair using the shipping labels provided to you.
The order will be processed during our regular business hours (Mon-Fri 8:30 – 5:00 EST). After processing your order, we will email shipping labels and shipping instructions. If you don’t see shipping labels within 1 hour of submitting your order (during business hours) please first check your junk/spam folders. If you still don’t see the labels, please contact us at 1-888-712-2525
Features:
Plug & Play: The software and settings will not be modified, making this module plug and play. No software reload or calibration is required after installation.
Quick Turnaround: Your module will be tested, repaired, tested again, and sent back to you in the same day (unless otherwise noted).
Quality Tested: All our Volvo ECMs undergo rigorous tests on our specialized custom built CAN-bus driven test bed. Functions, DTCs, and software are checked and verified for proper operation.*
Please note that since this is an Engine Control Module some functions can only be tested when installed in the vehicle with a working engine, meaning testing is limited outside of the vehicle. If you’re in doubt of whether or not your ECM is faulty, please consult with a Volvo specialist or contact our tech support by submitting a Technical Question Form here.
Reference Numbers
▼
Common Failure Symptoms
▼
Root Failure Cause: Shorted thermostat heater causes internal damage in the ECM, resulting in:
• ECM-P059700
• ECM-P059800
• ECM-P05990
• P0597
• P0171 “Thermostat Heater Control Circuit”
• New Thermostat heater is installed and codes still won’t clear
1 - 13 of 13 Posts
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