P0198 on Saab: Causes, Symptoms and Fix Cost
Quick Answer
Safe to drive (short-term)
P0198 on a Saab means the engine computer sees a voltage on the oil temperature sensor wire that is higher than a working sensor can produce. It usually points to an open circuit, such as a broken wire, an unplugged connector or a dead sensor, or to a short to the supply voltage. The oil itself is not necessarily hot. The computer then falls back on a fixed oil temperature. On many cars the sensor is a small screw-in part that is cheap to replace; on others it is part of a sump sensor that costs more.
- Severity
- Low · Electrical
- Typical repair cost, all makes
- €15-€420
Connect a standard OBD2 adapter (Bluetooth LE on iPhone) to your Saab and Skanyx tells you what P0198 means on that engine, whether it is safe to keep driving, and what the fix should cost. Free on iPhone and Android.
Get Skanyx freeWhat does P0198 mean on a Saab?
The Quick Answer above is the generic definition. What follows is the model-specific detail for the Saab models that log P0198.
Saab 9-5 (2.2 TiD diesel)
2002-2005
Saab's service page for the 9-5 2.2 TiD (control module PSG 16, engine D223L) lists P0198 as the oil temperature sensor circuit with a short to B+ or an open circuit. It sets when the sensor input rises above 4.96 V, and the computer then uses 100 C for oil temperature. The page warns that a fault in the female connector of the control module can also cause the code.
Source: saabwisonline.com, en.wikipedia.org
Saab 9-3 (first generation, 2.2 TiD)
1998-2003
On the same PSG 16 diesel control module, Saab's P0196 plausibility check (oil not above 50 C within 3 minutes of coolant passing 80 C) only runs when the fault criteria for P0117, P0118, P0197 and P0198 are not met, so fix the circuit fault first.
Source: saabwisonline.com, en.wikipedia.org
Sources
- saabwisonline.com saabwisonline.com/9-5-9600/2004/2-engine/psg-16-d223l/fault-diagnosis-diagnostic
- en.wikipedia.org en.wikipedia.org/wiki/Saab_9-5
- saabwisonline.com saabwisonline.com/9-3-9400/2003/2-engine/psg-16-d223l/fault-diagnosis-diagnostic
- en.wikipedia.org en.wikipedia.org/wiki/Saab_9-3
What causes P0198 on a Saab?
Beyond the generic causes listed on the main P0198 page, these are the patterns noted for Saab models:
Open circuit or short to B+ in the oil temperature sensor wiring
: Saab 9-5 (2.2 TiD diesel)
Bent or oxidised pin in the control module connector
: Saab 9-5 (2.2 TiD diesel)
Open circuit or short to B+ in the oil temperature sensor wiring
: Saab 9-3 (first generation, 2.2 TiD)
Failed sensor
: Saab 9-3 (first generation, 2.2 TiD)
How to diagnose P0198 on a Saab with OBD2
- Read the live oil temperature value. A reading frozen at an impossible number on a cold engine, whatever the car shows, suggests an open circuit or dead sensor
- Find the sensor from the service manual, as location differs: some screw into the block, others sit in the bottom of the sump. Inspect the plug and nearby wiring for chafing, oil soaking and corrosion
- Unplug the sensor and check with the key on for the reference voltage from the engine computer on the harness side. No reference voltage means a wiring or computer fault, not the sensor
- Measure the sensor with the plug disconnected. An open circuit reading means a dead sensor. Some combined sump sensors send a digital signal and cannot be tested this way, so use live data
- Check the connector pins at the engine computer end as well, since one bent or oxidised pin can set the code
- Repair the wiring or fit the new sensor, check and top up the oil, clear the code and make sure it stays out over a full warm-up
- Do not chase the oil temperature itself: a high circuit code is about voltage on the wire, not about how hot the oil is
How much does P0198 cost to fix on a Saab? (EUR)
Estimated repair costs for P0198 in EUR, compiled across makes. Saab costs typically sit in the middle of each range.
| Repair | Parts Cost | Labor Cost | Total Estimate | DIY Difficulty |
|---|---|---|---|---|
| Clean and reseat sensor connector | €0–€5 | €15–€40 | €15–€45 | Easy |
| Replace engine oil temperature sensor (DIY) | €20–€80 | €0–€0 | €20–€80 | Easy |
| Replace engine oil temperature sensor (shop) | €20–€80 | €50–€140 | €70–€220 | Moderate |
| Replace combined oil level and temperature sensor | €55–€220 | €80–€200 | €135–€420 | Moderate |
| Repair sensor wiring or connector | €5–€40 | €50–€140 | €55–€180 | Moderate |
Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.
Codes related to P0198
These codes are often seen alongside P0198 or point to related issues, on any make:
Looking for the full P0198 reference (all makes, full diagnosis flow, complete repair cost matrix)? See the main P0198 guide