VERACRUZ(EN) >2009 > G 3.8 DOHC > Fuel System > Engine Control System>P0197 Engine Oil Temperature Sensor Low Input  
Component Location

General Description
The fluid of the CVVT is the engine oil and its density changes according to the engine oil temperature. At this time the Oil Temperature Sensor (OTS) helps compensate against the temperature differences. The Oil Temperature Sensor measures the engine oil temperature before the engine oil comes into the Oil-flow Control Valve (OCV).
According to the measured temperature, the Engine Control Module (PCM) compensates the oil-flow control valve operation time.
DTC Description
Checking output signals from oil temperture sensor every 15 sec. under detecting condition, if an signal is low for more than 12.5 sec., PCM sets P0197. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC DEtecting Condition
Item
 Detecting Condition
 Possible cause
DTC Strategy
•
Signal low
•
Poor connection
•
Short to ground in harness
•
Oil temp.sensor
•
PCM
Enable Conditions
 Case 1
•
Engine running >60 sec
•
Coolant temperature < 110 °C(230°F)
Case 2
•
Engine running >90 sec.
Thresh old value
•
Oil temperature sensor's signal< 0.1V
Diagnosis Time
•
Continuous
(More than 12.5 sec.failure for every 15 sec.test)
MIL On Condition
•
2 Driving Cycles

Specification
Temperature(°C/°F)
 Resistance(kΩ)
-20°C/ -4°F
 16.52kΩ
20°C/ 68°F
 2.45kΩ
80°C/ 176°F
 0.29kΩ

Schematic Diagram

Monitor DTC Status
1.
Check DTC Status
(1)
Connect scantool to Data Link Connector(DLC).
(2)
IG "ON".
(3)
Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.
(4)
Read "DTC Status" parameter.

(5)
Is parameter displayed "Present fault"?

 ▶ Go to "Terminal and connector inspection" procedure.

 ▶ Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

Terminal And Connector Inspection
1.
Many malfunctions in the electrical system are caused by poor harness and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3.
Has a problem been found?

 ▶ Repair or replace if necessary and go to "Verification of Vehicle Repair" procedure

 ▶ Go to "Signal Circuit Inspection" procedure.

Signal Circuit Inspection
■ Check Voltage
1.
IG "OFF" & ENG "OFF".
2.
Disconnect OTS connector.
3.
IG "ON" & ENG "OFF".
4.
Measure voltage between signal terminal of OTS harness connector and chassis ground.
Specification : Approx. 5V
5.
Is the measured voltage within specification ?

 ▶ Go to " Component Inspection" procedure.

 ▶ Repair short to ground in harness, and go to "Verification of Vehicle Repair" procedure.

Component Inspection
■ Check OTS Resistance
1.
IG "ON" & ENG "OFF"
2.
Monitor Oil Temperature parameter on the scantool
3.
IG "OFF" & ENG "OFF"
4.
Disconnect OTS connector.
5.
Measure resistance between signal and ground terminals of OTS connector after checking out the oil temperature with scantool.
Specification :
Temperature(°C/°F)
 Resistance(kΩ)
-20°C/ -4°F
 16.52kΩ
20°C/ 68°F
 2.45kΩ
80°C/ 176°F
 0.29kΩ

6.
Is the measured resistance within specification ?

 ▶ Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

 ▶ Substitute with a known - good OTS and check for proper operation. If the problem is corrected, replace OTS and go to "Verification of Vehicle Repair" procedure.

Verification Of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1.
Connect scantool and select "DTC" button.
2.
Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3.
Read "DTC Status" parameter
4.
Is parameter displayed "History(Not Present) fault"?

 ▶ System performing to specification at this time. Clear the DTC

 ▶ Go to the applicable troubleshooting procedure.