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Home >> Volvo >> 1998 >> S90 L6-2.9L VIN 96 B6304S >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> AT / DTC Codes (Transmission Control Module) >> AT-142 Oil Temperature Sensor >> Signal Too High

Signal Too High





Checking Oil Temperature
- Ignition ON.
- Go into scrolling values.
- Read off oil temperature.
- Check that the transmission oil temperature is within bounds. Compare with the transmission temperature.
- Is the oil temperature within bounds?

Yes:
- Proceed to: Intermittent Fault section below.

No:
- Proceed to: Checking Ground Lead section below.





Checking Ground Lead
- Ignition OFF.
- Raise the car to access the transmission.
- Carefully clean round connector B.
- Disconnect transmission connector B.
- Connect an ohmmeter between transmission connector B terminal 4 (transmission control module (TCM) side) and ground.
- The ohmmeter should read approx. 0 Ohms.

If reading is OK:
- Proceed to: Checking Signal Cable section below.

If reading is incorrect:
- Proceed to: Checking The Transmission Control Module Connector section below.





Checking The Transmission Control Module Connector
- Ignition OFF.
- Transmission connector B disconnected.
- Check transmission control module connector for contact resistance and oxidation and remedy.
- Transmission control module connected.
- Connect an ohmmeter between transmission connector B terminal 4 (transmission control module side) and ground.
- The ohmmeter should read approx. 0 Ohms.

If reading is OK:
- Proceed to: Fault-tracing Information section below.

If reading is incorrect:
- Proceed to: Checking For An Open-circuit section below.

Fault-tracing Information
- The diagnostic trouble code (DTC) was caused by loose connections in the transmission control module connector.
- Proceed to: Verification section below.





Checking For An Open-circuit
- Check cable between transmission connector B terminal 4 and transmission control module # 19 for an open-circuit.
- Proceed to: Verification section below.





Checking Signal Cable
- Ignition OFF.
- Transmission connector B disconnected.
- Ignition ON.
- Connect a voltmeter between transmission connector B terminal 3 (transmission control module side) and ground.
- The voltmeter should read approx. 5 Volts.

If reading is OK:
- Proceed to: Checking Oil Temperature Sensor Resistance section below.

If value is lower:
- Proceed to: Checking The Transmission Control Module Connector section below.

If value is higher:
- Proceed to: Checking For A Short-circuit To Supply Voltage section below.





Checking For A Short-circuit To Supply Voltage
- Check cable between transmission connector B terminal 3 and transmission control module # A34 for a short-circuit to supply voltage.
- Proceed to: Checking Oil Temperature Sensor section below.





Checking The Transmission Control Module Connector
- Ignition OFF.
- Disconnect transmission connector.
- Check transmission control module connector for contact resistance and oxidation and remedy.
- Transmission control module connected.
- Ignition ON.
- Connect a voltmeter between transmission connector B terminal 3 (transmission control module side) and ground.
- The voltmeter should read approx. 5 Volts.

If reading is OK:
- Proceed to: Fault-tracing Information section above.

If reading is incorrect:
- Proceed to: Checking For An Open-circuit section below.





Checking For An Open-circuit
- Check cable between transmission connector 6 terminal 3 and transmission control module # A34 for an open-circuit.
- Proceed to: Verification section below.





Checking Oil Temperature Sensor Resistance
- Ignition OFF.
- Disconnect transmission connector.
- Connect an ohmmeter between transmission connector B, terminals 3 and 4 (transmission side). Compare the temperature below with the transmission temperature at the oil temperature sensor.





- The ohmmeter should read 765-1035 Ohms at +20°C (68°F), (see image).

If reading is OK:
- Proceed to: Remedy Contact Resistance And Oxidation section below.

If reading is incorrect:
- Proceed to: Checking For An Open-circuit section below.





Remedy Contact Resistance And Oxidation
- The diagnostic trouble code has been caused by poor contact in the transmission and transmission control module connectors.
- Check connector for contact resistance and oxidation and remedy.
- Proceed to: Verification section below.





Checking For An Open-circuit
- Check cables between oil temperature sensor and transmission connector B terminals 3 and 4 for an open circuit.
- Are cables OK?

Yes:
- Proceed to: Replacing Component section below.

No:
- Proceed to: Verification section below.





Checking Oil Temperature Sensor
- The oil temperature sensor can malfunction due to a short-circuit to supply voltage in the signal cable.
- Check signal cable as follows:

- Ignition OFF.
- Disconnect transmission connector.

- Connect an ohmmeter between transmission connector B, terminals 3 and 4 (transmission side).
- The ohmmeter should read 765-1035 Ohms, (see image).

If reading is OK:
- Proceed to: Verification section below.

If reading is Incorrect:
- Proceed to: Replacing Component section below.

Replacing Component
- Try a new oil temperature sensor.
- Proceed to: Verification section below.





Verification
- After repairs have been completed they must be verified as follows to ensure that the fault has been eliminated:

- Ignition OFF.
- Reconnect connectors, reinstall components etc.
- Ignition ON.
- Go into scrolling values.
- Read off oil temperature.
- Check that the transmission oil temperature is within bounds. Compare with the transmission temperature.

- Is the oil temperature within bounds?

Yes:
- Fault corrected.

No:
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
- Fault not corrected.

No:
- Proceed to: Checking Oil Temperature section above.





Intermittent Fault
- Check transmission and transmission control module connectors for loose connections and oxidation.
- Check the cable between the oil temperature sensor and transmission control module # 34 for an intermittent open-circuit and an intermittent short-circuit to supply voltage.
- Check the cable between the oil temperature sensor and transmission control module # 19 for an intermittent open-circuit.
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.

- Do you want to repeat fault-tracing?

Yes:
- Proceed to: Checking Oil Temperature section above.

No:
- Operation done.
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