P0197 Code Meaning and Next Steps

First checks take 10 minutes for basic checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!There is overheating, steam, or a visible coolant leak.
!The temperature gauge moves toward hot or the engine starts running much worse than normal.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored if drivability changes are obvious.

What to check first

Step-by-step checks

1
Safety first
Let the engine cool before inspecting the sensor, connector, or any hot oil-area components
2
Free - no tools
Check whether the oil temperature reading is obviously stuck low on a warm engine
3
Basic tool needed
Inspect the connector and harness for oil contamination, broken insulation, or a short-to-ground condition
4
Basic tool needed
Look for recent repair work around the filter housing or oil sensor area that may have disturbed the wiring
5
Basic tool needed
If scan data is available, compare the reported temperature with the engine's actual warm-up behavior before ordering parts
6
Basic tool needed
If the vehicle also has lubrication or overheating symptoms, treat those as separate problems rather than assuming the sensor is the whole story

If the code returns

-If the reading stays unrealistically cold, the sensor or circuit is more likely than the oil itself.
-If the connector changes the reading when moved, repair the wiring before replacing the sensor.
-If the code appears after the engine is hot and then clears cold, the harness or sensor may be heat-sensitive.

Background

What this code means

P0197 is a generic OBD-II code for a low-input engine oil temperature sensor signal.

That usually means the ECU is seeing a signal that suggests the oil is much colder than it really is, or the circuit is being pulled low by a wiring fault. A sensor issue is common, but connector contamination and harness damage can look the same.

Diagnosis

Common causes

Most common

Shorted sensor circuit

A short-to-ground can pull the signal low and make the ECU think the oil is colder than it is.

Common

Faulty oil temperature sensor

The sensor may be internally shorted or biased low.

Common

Connector contamination

Oil, corrosion, or moisture in the connector can distort the signal.

Possible

Harness damage near heat

A wire worn through or heat-damaged near the engine can create a false-low reading.

Avoid these mistakes

What not to do

xDo not assume the oil is actually cold if the engine has already warmed up normally.
xDo not inspect hot engine components without letting them cool first.

Parts

Parts that may need replacing

PartTypical costNotes

Engine oil temperature sensor$20-$90Most relevant when the circuit is intact but the reading stays too low.

Connector or wiring repair$20-$160Often the actual fix when the signal is being pulled low by damage or corrosion.

Oil leak or sealing repairVariesUseful when oil intrusion at the connector is part of the fault.

Related OBD codes

P0195

P0195 means the engine oil temperature sensor circuit is not working properly.

P0196

P0196 means the engine oil temperature sensor is reading outside the expected range.

P0198

P0198 means the engine oil temperature sensor is reading too high.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0197 was seeded from dtcdb and then expanded around low-input engine oil temperature faults, especially shorted circuits, failed sensors, and contaminated connectors.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0197 - The Engine Oil Temperature Sensor Is Reading Too Low