The Volvo V60 with T6 and T8 hybrid powertrain regularly suffers from specific ECM faults (Engine Control Module; the engine computer). The system runs too lean due to leaks or defective turbo and supercharger components. In addition, the suspension system often reports faults related to the VCM module (Volvo Control Module; the central control unit for suspension and ride height) and its associated backup battery. These issues are not exceptions, but occur regularly among owners of these hybrid models. Do you want to know what these faults mean and how to deal with them?
What does the ECM-P017100 fault mean?
The fault code ECM-P017100 indicates a system that is running too lean, which means that the engine is drawing in more air than expected in relation to the amount of fuel. On the Volvo V60 with T6 or T8 powertrain this fault has various causes. The most common culprits are a leaking supercharger, damaged or loose air pipes, a cracked turbo or a faulty catalytic converter.
This fault code does not appear out of nowhere. The engine management system detects that the air–fuel ratio is incorrect, which can lead to loss of power and increased fuel consumption. In some cases, the car switches to a limp mode in which the engine power is limited to prevent further damage.
The underlying causes vary greatly. That is why a thorough diagnostic check is necessary before starting any repairs. A specialist can use professional diagnostic equipment to determine the exact cause and thus avoid unnecessary repair costs.
Suspension faults on the Volvo V60 hybrid
Many V60 T6 and T8 owners report suspension faults related to the VCM module. This module contains a built-in backup battery that can fail over time. This leads to specific fault codes such as SUM-C103B4B for the air suspension compressor and VCM-U105000 for the backup battery life.
These faults are not unexpected defects, but rather wear parts that need to be replaced at regular intervals as the vehicle ages. The backup battery ensures that certain systems retain their settings. The main battery can then be safely disconnected without loss of data. When this backup battery fails, suspension settings can be lost and the system may no longer function correctly.
Symptoms of a faulty VCM backup battery
The following symptoms point to a possible faulty backup battery in the VCM module:
- Suspension system warning light stays on continuously
- Fault message about air suspension compressor
- Loss of ride-height settings after starting
- Suspension switches to limp mode with fixed damping
The VCM module is located in the engine bay and is relatively easy to access for replacement. Some owners choose to have the module replaced preventively before faults occur, especially on vehicles older than five years.
Risks of continuing to drive with ECM faults
On V60 T6 and T8 models, the thermostat plays a special role. Many of these engines are fitted with a thermostat with a wax element that can fail over time. At first sight this seems like a minor issue, but continuing to drive with this fault can have serious consequences.
A faulty thermostat can lead to the engine overheating. This increases the risk of a failed ECM engine computer or even a blown head gasket. Repair costs for this type of damage can quickly add up to several thousand euros. It is therefore important to take warning lights relating to coolant temperature seriously.
Warning signs of thermostat and cooling system problems
Watch out for the following signs that may indicate thermostat or cooling system problems:
- Engine reaches operating temperature more slowly than normal
- Temperature gauge fluctuates irregularly while driving
- Heater does not blow consistently warm air
- Engine temperature warning light comes on
If you are unsure about the condition of the cooling system, it is wise to have it checked in good time. This will prevent much more expensive repairs at a later stage.
Inverter module defects in plug-in hybrid models
A specific problem on the T8 plug-in hybrid version is failure of the inverter module. This component is located under the high-voltage battery. The module is programmed specifically for each vehicle. As a result, replacement with a used unit is not possible.
When one of the IGBT transistors in the inverter fails, a catastrophic fault occurs in which the vehicle will no longer start. The car will then run neither on petrol/diesel nor on electric power. This type of defect always requires professional repair with a new or refurbished inverter module that must be reprogrammed for your specific vehicle.
The costs of this repair can be high, as both the component itself and the programming and installation require specialist knowledge. Unfortunately, there are few preventive measures you can take against this type of defect.
‘ This type of preventive maintenance can prevent expensive repairs in the long run. ’
Preventive maintenance for the ERAD unit
A practical maintenance tip that helps prevent problems: replace the ERAD oil (Electric Rear Axle Drive; the electric drive of the rear wheels) as preventive maintenance. This type of maintenance is not included in Volvo’s standard maintenance schedule, but can help prevent problems with the electric motor and clutch.
ERAD oil ages just like other lubricants and can lose its protective properties over time. By replacing this oil in good time, you reduce the risk of wear on the electric drivetrain. This type of preventive maintenance can prevent expensive repairs in the long term.
When professional help is necessary
Although some diagnostic steps can be carried out by owners themselves, most ECM-related problems require professional repair. The complexity of the hybrid system and the need for specialist reprogramming usually make DIY repair impractical.
On P3 chassis models such as the V60, the ECM is located under the engine cover. On newer P5 chassis models the ECM is located in the drainage area behind the front wing on the driver’s side. This is the space where rainwater from the wing is collected. For inspection or replacement, the battery must always be disconnected first to prevent short circuits and damage to the system.
Steps for ECM diagnosis by professionals
A specialist will usually carry out the following steps when dealing with ECM faults:
- Reading fault codes with professional diagnostic equipment
- Checking air pipes and connections for leaks
- Inspecting turbo and supercharger for mechanical damage
- Testing sensors and actuators in the fuel system
- Verifying ECM software and any available updates
This methodical approach helps to find the exact cause without replacing unnecessary parts. That saves time and money.
More information about Volvo V60 problems
ECM faults and suspension issues are only part of the potential technical points of attention. The Volvo V60 T6 and T8 hybrid models have several specific challenges. On the Carnews website you will find extensive information about other common problems, maintenance schedules and practical tips for these models. Discover more about the technology behind modern hybrid powertrains and learn how to keep your Volvo in optimum condition.
Frequently asked questions
The most common ECM-related fault on the Volvo V60 T6 and T8 hybrids is fault code ECM‑P017100 (“system too lean”), often due to leakage or damage in the supercharger/turbo and air intake tract or a defective catalytic converter. In addition, there are regular problems with the VCM module and the backup battery integrated into it (such as VCM‑U105000), which can cause hybrid and comfort-related faults. Cooling and thermostat problems (failed wax element) are also common and can indirectly lead to serious engine damage and ECM issues. In plug-in hybrids, defective inverter modules (IGBT failures) also occur, leading to severe powertrain faults.
Symptoms of an ECM fault in a Volvo V60 T6/T8 hybrid often include messages such as “Reduced Engine Performance” and the car going into limp mode (limited engine performance). You may also experience fault code ECM‑P017100 (system too lean), a rough or uneven-running engine and sometimes severe loss of power. With related VCM/backup battery problems, specific fault codes such as VCM‑U105000 appear and hybrid functions may partially or completely drop out. With serious ECM or inverter problems, the car may eventually no longer start at all, neither on fuel nor electrically.
On the Volvo V60 T6 and T8 hybrids, ECM faults are often caused by a lean mixture (for example due to a leaking supercharger, damaged air pipes, cracked turbo or defective catalytic converter). In addition, cooling system problems, such as a failing thermostat with wax element, can lead to overheating and damage to the ECM. Ageing or faulty components in the hybrid system, such as the VCM module with backup battery or the inverter module (IGBT defects), can also trigger fault codes and ECM-related issues. Preventive maintenance, such as timely replacement of ERAD oil and regular diagnostics, reduces the likelihood of these faults.
Start by reading out the fault codes (preferably with VIDA/Volvo diagnostic equipment) and note all ECM and hybrid-related codes, such as ECM-P017100, SUM-C103B4B and VCM-U105000. Visually inspect connections and wiring looms around the ECM and VCM for corrosion, water damage (especially after driving through deep water) and mechanical damage, and check the condition of the backup battery in the VCM module. Then examine the air and boost side for leaks or defects (supercharger, turbo, pipes, catalytic converter) and check the cooling system/thermostat for correct operation to prevent engine damage and ECM damage. In the case of persistent or complex faults (for example inverter or ERAD problems, limp mode or “Reduced Engine Performance”), do not continue to use the car and call in a specialist with Volvo experience for further diagnosis and any reprogramming.
Untreated ECM faults can lead to a lean-running mixture, loss of power, irregular engine behaviour and the car going into “Reduced Engine Performance” or limp mode more often. Driving for a long time with such faults can cause overheating and additional mechanical stress, with a risk of damage to components such as the head gasket, catalytic converter and even the ECM itself. On hybrid T6/T8 systems, it can also disrupt the interaction between the combustion engine, electric motor and inverter, causing starting problems and reduced electric assistance. Ultimately, this can significantly shorten the lifespan of both the powertrain and expensive hybrid components.
Regular preventive maintenance is important: have the ERAD oil changed in good time, even if this is not specified in the standard maintenance schedule. Make sure that the cooling system, and the thermostat in particular, remain in good condition, as overheating can cause serious damage to the ECM. Avoid driving through deep water and, after wading through water, check that the ECM area is dry to prevent moisture and corrosion damage. If you get fault codes such as P017100 or VCM/backup battery errors, have a specialist find the cause in good time to limit consequential damage to the engine management system.