P0198 on 2016-2019 Volkswagen Jetta: Engine Oil Temperature Sensor Circuit High

What's Unique About the 2016-2019 Volkswagen JETTA

For many modern Volkswagens, including the Jetta, the engine oil temperature sensor is integrated into the oil level sensor (often designated as G266). This combined unit is mounted in the bottom of the oil pan. This design means that a failure of either the level or temperature sensing component requires replacing the entire unit, which involves draining the engine oil. The issue is common enough that VW issued technical service bulletins for 2016-2017 models mentioning P0198 alongside a yellow oil warning light.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: This range covers two Jetta generations: the end of the Mk6 (A6, through 2018) and the start of the Mk7 (A7, from 2019). While the specific engines and some electronics differ (e.g., 1.4TSI, 1.8TSI, 2.0TSI), the function and common failure modes of the G266 oil temperature/level sensor circuit are fundamentally the same across both generations for this code.

Symptoms You May Notice

• Check Engine Light is on
• Yellow oil warning light on the dashboard, may say "Oil sensor workshop!".
• Engine may enter 'limp mode' with reduced power.
• Inaccurate or wildly fluctuating oil temperature gauge (if equipped)
• Slightly reduced fuel economy.
• Scanner data shows a static, extreme temperature reading like -40°C or -48°C, which is a typical ECU default for an open circuit.

Most Likely Causes

1. Failed Engine Oil Level/Temperature Sensor (G266) 🔴 High Probability The sensor is located at the bottom of the engine, exposed to heat cycles and potential road debris. Internal failure of the thermistor can create an open circuit, which the PCM interprets as a high voltage signal. Aftermarket sensors are also known to fail prematurely or be faulty out of the box.
   How to confirm: With a diagnostic scanner (like VCDS), check the live data for the Engine Oil Temperature. If it shows an extreme, unchanging value (e.g., -40°F/-40°C or over 250°F) even with a cold engine, the sensor or its circuit is faulty. You can also test the sensor's resistance with a multimeter; an infinite resistance reading indicates an open circuit. However, testing these specific combined sensors can be inconclusive without a proper service manual procedure.
   Typical fix: Replace the oil level/temperature sensor. This requires draining the engine oil to access the sensor at the bottom of the oil pan. The sensor is typically held in by three 10mm nuts, which should be torqued to approximately 8 ft-lbs (around 10-11 Nm). Always use a new gasket.
   Est. part cost: $50-$150
2. Wiring or Connector Issue 🟡 Medium Probability The wiring harness to the oil pan can be damaged by road debris, improper servicing, or corrosion over time. The connector itself can also become loose or contaminated with oil. In some cases, the locking tab on the connector breaks, allowing it to back off and create an open circuit.
   How to confirm: Visually inspect the wiring harness from the oil pan sensor up to the main engine harness. Look for any breaks, chafing, or melted insulation. Disconnect the sensor and check the connector pins for corrosion or oil contamination. A real-world example from a Ross-Tech forum on a 2015 VW Golf with P0198 found the cause to be a loose connector with a broken locking tab. Pushing it back on and securing it with safety wire resolved the fault. Use a multimeter to check for continuity between the PCM and the sensor connector.
   Typical fix: Repair the damaged section of the wiring harness. Clean the connector with electrical contact cleaner. If the connector's locking tab is broken, secure it firmly with a zip tie or safety wire after ensuring a solid connection. Replace the connector pigtail if it's damaged beyond repair.
   Est. part cost: $10-$50

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is very rare. Before condemning the PCM, all other possibilities, including the sensor and wiring, must be exhaustively tested and ruled out. A PCM failure for a single sensor circuit is highly unlikely.

Diagnosis Steps

1. Connect an OBD-II scanner and confirm P0198 is present. Check for any other related codes, especially P0196.
2. View live data for the Engine Oil Temperature (EOT). A static, extremely high or low reading (e.g., >250°F or -40°C/-48°C) on a cold engine points to a circuit fault.
3. Perform a visual inspection of the oil level/temperature sensor connector and its wiring harness at the bottom of the oil pan. Pay close attention to the connector's locking tab to see if it's broken or loose. Check for wires rubbing against the oil pan or other components.
4. If the wiring looks good, disconnect the sensor. The code may change to a 'Circuit Low' code, which can help confirm the wiring is likely intact to the PCM.
5. With the key on and sensor disconnected, use a multimeter to check for reference voltage (typically 5V) and a good ground at the connector.
6. If reference voltage and ground are good, the sensor itself is the most likely culprit. 🎬 See how to test and replace the oil temperature sensor. Test the sensor's internal resistance; it should match the specifications in a repair manual. Infinite resistance means the sensor has failed open.
7. If the sensor tests good, perform a continuity test on the signal wire between the sensor connector and the PCM to find a potential break in the wire.

Parts You'll Likely Need

• Engine Oil Level and Temperature Sensor (OEM #06E907660 (Note: Part number can vary by specific engine. Always verify with VIN.)) — This is the most common point of failure for a P0198 code, as the internal thermistor fails and creates an open circuit.
  Trusted brands: Hella, Bosch, Febi Bilstein, OEM Volkswagen
  OEM price range: $100-$180
  Aftermarket price range: $50-$120

Related Codes That Often Appear With This One

• P0196 — P0196 is 'Engine Oil Temperature Sensor Range/Performance'. It is often triggered along with P0198 as the PCM sees the signal is not just high, but also irrational or out of its expected performance range. The VW TSB VIN-4-A-PIN-2018 explicitly links these two codes.

Technical Service Bulletins (TSBs) & Recalls

• VIN-4-A-PIN-2018: Mentions the yellow oil warning light on with fault P0198 for 2016 and 2017 Jetta models.

Platform-Specific Known Issues

• Volkswagen Technical Service Bulletin (TSB) #VIN-4-A-PIN-2018 for 2016 and 2017 Jetta models notes that a yellow oil warning light may appear with fault code P0198 (or P0196). This bulletin is a compilation of multiple common issues and confirms the link between the code and a driver complaint, but does not provide a unique repair procedure for it.
• A common failure point is not the sensor or wiring itself, but the plastic locking tab on the electrical connector. If broken during a previous service (like an oil change), the connector can vibrate loose, creating an open circuit and triggering P0198.

Mechanic-Grade Diagnostic Values

• G266 Sensor Connector Pin Test (Key On, Connector Off) — expected: Pin 1: +12V DC, Pin 2: Ground (less than 1 ohm to chassis ground). Failure: No voltage on Pin 1 indicates a power supply issue (fuse, wiring). High resistance on Pin 2 indicates a bad ground connection.
• VCDS Live Data - Open Circuit Default — expected: A normally functioning sensor will show a plausible temperature that changes as the engine warms up.. Failure: A reading of -48°C is a typical default value shown by the ECU when it detects an open circuit to the sensor.

Scan Tool Commands That Help

• VCDS (VAG-COM): Adaptation in Instrument Cluster (17) — In some older models, it's possible to code out the oil level sensor warning if the vehicle is no longer on a LongLife service interval. This is generally not recommended as a 'fix' for a faulty sensor or circuit, but as a temporary measure or for specific custom applications. The channel is often labeled 'SIE' (Service Interval Extension) and involves changing a value related to 'TOG' (Thermal Oil-level Gauge).

Wiring & Ground Locations

• G266 Sensor Connector — Plugged into the oil level/temperature sensor, which is mounted to the bottom of the engine oil pan.. This is the primary connection point. It is susceptible to oil contamination, corrosion, and physical damage from road debris or improper service (e.g., broken locking tab). A poor connection here is a direct cause of P0198.
• Engine Block Ground Strap — A braided metal strap connecting the engine block to the vehicle's chassis/frame.. While not a direct cause, a poor or missing engine ground can cause electrical noise and voltage potential differences across the chassis, leading to erratic sensor behavior. In one documented case (though not on a Jetta), installing a high-output alternator with improper grounding caused a P0198 code because the electrical current was seeking a path through sensor grounds.

Real Owner Repair Stories

• Ross-Tech Forums user 'MrNomad105' (2015 VW Golf MKVII (platform-mate to Jetta with similar systems)) — Check Engine Light with codes P0196 and P0198. VCDS showed engine block temperature at a default -48°C.
  ❌ Tried (didn't work) Initial diagnosis pointed towards a bad sensor.
  ✅ What actually fixed it The locking tab on the sensor's electrical connector was broken, causing it to become partially disconnected. The user pushed the connector back on securely and used aviation safety wire to hold it in place. This resolved the fault codes without replacing any parts.

OEM Part Supersession History

• 03F907660E (For some EA888 Gen 3 engines) → 06K907637B — Part revision/update by the manufacturer.
  Heads up: The new part 06K907637B is noted as NOT being suitable for GPF (Gasoline Particulate Filter) models.
• Multiple, including 03F907660C, 03F907660D → 03F907660E (itself now superseded for some applications) — Standard part evolution and consolidation.
  Heads up: Part numbers are highly specific to the engine type (EA211 vs EA888) and model year. Always verify with VIN.

Model Year Variations Within This Range

• 2016-2018 (Mk6 with 1.8T/2.0T EA888 Gen 3) and 2019+ (Mk7 with 2.0T EA888 Gen 3): The oil level/temperature sensor part number may be 06K907637B (superceding from 03F907660E). It's crucial to verify fitment as there are variations.
• 2016-2018 (Mk6 with 1.4T EA211) and 2019+ (Mk7 with 1.4T EA211): The oil level/temperature sensor part number is typically 04E907660C for the 1.4TSI engine.
• 2016-2018 (Mk6): The Pass 2-cited OEM part number 06E907660 is more commonly associated with larger Audi/VW engines (like the 3.0T) and may be incorrect for the Jetta in this year range, highlighting the need to verify by VIN.