P190E – Coolant Pump for Intercooler (VW)

By Reinier (Contact Me)
Last Updated 2023-03-28
Automobile Repair Shop Owner

Table of Contents

1. What Does Code P190E Mean?
2. Where is the P190E sensor located?
3. What are the common causes of code P190E?
4. What are the symptoms of code P190E?
5. Get Help with P190E

What Does Code P190E Mean?

SPECIAL NOTES: Be aware that VW/VAG-specific trouble code P190E refers specifically to issues with a coolant pump that supplies engine coolant to the water-to-air inter-cooler on turbo diesel engines. However, there is also a generic code, DTC P261A/B/C/D that refers to issues with an electric pump that supplies engine coolant to a water-to-air inter-cooler on VW/VAG turbo diesel engines.

For reasons that are not clear, VW/VAG DTC P190E is not listed in most official VW/VAG sources or most unofficial code lookup tools. Moreover, the terms “Auxiliary Coolant Pump”, “Coolant Pump B“, Coolant Pump for Inter-cooler” and “Charge Air Coolant Pump” are all associated with generic code P261A/B/C/D in almost all technical resources, while the term “Coolant Pump for Inter-cooler” is only very rarely associated with VW/VAG-specific DTC P190E.

This state of confusion is made worse by the fact that only VW/VAG-specific scan tools are programmed to display trouble code P190E. In practice, this means that even high-end generic scan tools and code readers will display generic trouble code P261A/B/C/D, and refer to the inter-cooler’s coolant pump as either the “Coolant Pump “B”, “Auxiliary Coolant Pump” or “Charge Air Coolant Pump” when they detect issues with the inter-cooler’s coolant pump. 

Nonetheless, the above does not mean that generic trouble code P261A/B/C/D and VW/VAG-specific DTC P190E are in any way interchangeable, because VW/VAG defines DTC P190E as “ “Coolant Pump for Inter-cooler – supply voltage”, while this definition does not apply to any variant of trouble code P261A/B/C/D, which are variously defined as –

• P261A – Coolant Pump “B” Control Circuit/Open
• P261B – Coolant Pump “B” Control Circuit Range/Performance
• P261C – Coolant Pump “B” Control Circuit Low
• P261D – Coolant Pump “B” Control Circuit High

On a purely practical level, however, it does not matter much which trouble code a scan tool displays because the terms “Auxiliary Coolant Pump”, “Coolant Pump B“, Coolant Pump for Inter-cooler” and “Charge Air Coolant Pump” can safely be used interchangeably, even though DTC P190E has a strictly defined meaning. END OF SPECIAL NOTES.

OBD II fault code P190E is a manufacturer-specific trouble code that is defined by carmaker VW/VAG (and all related vehicle makes) as P190E – “Coolant Pump for Inter-cooler- Supply Voltage”, and is set when the PCM (Powertrain Control Module) detects a fault or defect or malfunction in the electrical circuits of the pump that circulates coolant through the inter-cooler. Note that this code applies only to vehicles that have water-to-air inter-coolers: note that many, if not most VW/VAG and related vehicles have simple air-to-air inter-coolers.

Although forced induction engines are vastly more efficient than naturally aspirated engines, the act of compressing the intake air with a turbocharger greatly increases the temperature of the compressed air. Moreover, since hot air expands, much of the advantage of compressing the intake air in the first place is lost because hot air takes up a greater volume than cold air.

In practice, the purpose of forced induction is to compress the intake air into as small a volume as possible to make it possible to squeeze as much air as possible into the engine’s cylinders,  because forcing more air into the cylinders makes it possible to add more fuel to the air/fuel mixture. Note that even during maximum boost conditions, the volume of air being forced into the engine will always be matched to the amount of fuel being injected, which maintains an ideal ratio of air/to fuel under most engine operating conditions.

Thus, to keep the temperature of the intake air as low as possible, the compressed intake air is passed through a kind of radiator, known as an “inter-cooler” that sheds most of the compressed intake air’s heat, in much the same way that a radiator sheds the engine coolant’s heat to the atmosphere. As a practical matter, using the airflow caused by the vehicle’s forward motion as a means to cool the intake air down is reasonably effective, but the cooling effect is greatly increased when a liquid, engine coolant in this case, is passed through the inter-cooler as well.

The combined effect of air flowing across the inter-cooler, and engine coolant circulating through dedicated water jackets in the inter-cooler is far greater than is possible to achieve with either method on its own. As an added advantage, passing engine coolant through the inter-cooler has the effect of increasing the efficiency of the engine cooling system as a whole, since the air flowing through the inter-cooler sheds some of the coolant’s heat as well.

Although some aspects of cooling the intake air down vary somewhat between VW/VAG applications, all such systems work in the same way. Some engine coolant is diverted from the main coolant circulation pattern, and fed to an electric pump (via a dedicated hose) that forces the coolant through the inter-cooler. Upon exiting the inter-cooler, the coolant is returned to the main circulation pattern via a dedicated hose. Note, though, that in some cases, the diverted coolant also passes through the cabin heater, although the flow of coolant through the heater matrix is controlled by a valve that can be shut off either manually, or electronically, depending on the vehicle model.

Note also that although the flow of coolant through the inter-cooler is not critical to the engine’s operation, any fault or defect in the inter-cooler system that impedes or prevents the flow of coolant through the inter-cooler can potentially affect the engine’s efficiency. Thus, if the PCM detects a fault or failure in the inter-cooler’s coolant pump or its associated wiring, it will recognize that the intake air is not being cooled optimally, and it will set code P190E, and illuminate a warning light as a result.

Where is the P190E sensor located?

This image shows the location and appearance of the inter-cooler coolant pump on a circa 2015 application. In this view, the radiator had been removed for clarity, meaning that the pump is located between the engine and the radiator. While this is the general location of the inter-cooler pump on all equipped VW/VAG vehicles, the actual location and method of attachment vary somewhat between applications.

WARNING: The inter-cooler pump must not be confused with the “after-run pump” whose only function is to circulate coolant through the turbocharger for a set time after the engine is shut off. To avoid confusion and misdiagnoses, we strongly recommend that you research the actual location of the inter-cooler pump on the affected vehicle before committing to a replacement of this pump on a DIY basis.

What are the common causes of code P190E?

Although inter-cooler pumps on VW/VAG vehicles fail for relatively few reasons, failure of these pumps is nevertheless extremely common. The most common causes could include one or more of the following-

• Damaged, burnt, shorted, corroded, or disconnected wiring in the pump’s wiring harness. Note that since the pump itself is a part of the control system, an electrical failure of the pump itself could cause this code to set
• Mechanical damage to the pump’s bearings, seals, or impeller caused by corrosion
• Low coolant level for any reason
• Failure to bleed the cooling system correctly after cooling system repairs
• The use of substandard aftermarket pumps
• Degraded, dirty, or contaminated engine coolant

What are the symptoms of code P190E?

The most common symptoms of code P190E are largely similar across all equipped applications, but note that unless the cause of this code has caused engine coolant to be lost and the engine fails catastrophically, this code will typically not produce noticeable (if any) drivability concerns-

• Stored trouble code and an illuminated warning light
• In some cases, additional trouble codes may be present along with P190E
• A low coolant level is possible
• Increased emission levels and decreased fuel economy may occur under some operating conditions
• The vehicle may not pass an emissions test

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