Operation CHARM: Car repair manuals for everyone.

Signal Too High






SPECIAL TOOLS
Test box tool No. 981 3190, or equivalent
Volvo scan tool No. 998 8686, or equivalent

TOO HIGH
1. Other Diagnostic Trouble Codes (DTCs)
- Read off OTHER DTCs.
- Is DTC AT-141 stored?
YES: Proceed to step 2
NO: Proceed to step 3
2. Fault-tracing information
- Fault-trace according to DTC AT-141: Oil Temperature Sensor, Signal Too Low. Signal Too Low
- Then continue with step 13





3. Checking oil temperature
- Preparation:
Ignition ON
Select scrolling values
Read off transmission oil temperature
- Check that the transmission oil temperature is within bounds.
- Compare with the temperature of the transmission itself.
- Is the oil temperature within bounds?
YES: Proceed to step 5
NO: Proceed to step 4





4. Checking oil temperature sensor signal cable
- Preparation:
Ignition OFF
Remove the Air Cleaner (ACL) housing to access the transmission connector.
Disconnect the transmission connector
- Connect an ohmmeter between the transmission connector terminal 12 (transmission side) and the transmission housing.
- The ohmmeter should read infinite resistance.
- If reading is OK:
Proceed to step 6
- If reading is incorrect:
Proceed to step 5





5. Checking for short-circuit and replacing component
- Preparation:
Ignition OFF
- Check cable between oil temperature sensor and transmission connector terminal 12 for a short-circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- If the cable is OK, try a new oil temperature sensor, refer to replacement Service and Repair.
- Then continue with step 13





6. Checking oil temperature sensor resistance
- Preparation:
Ignition OFF
Disconnect transmission connector
- Connect an ohmmeter between the transmission connector terminals 12 and 13 (transmission side).
- The ohmmeter should read approximately 765-1035 Ohms at +20°C (see table below).
- Compare the temperature below with the transmission temperature at the oil temperature sensor

Temperature/Resistance Table
Temperature: 0°C
Resistance (Ohms): 1700-2300
Temperature: 20°C
Resistance (Ohms): 765-1035
Temperature: 40°C
Resistance (Ohms): 340-460
Temperature: 80°C
Resistance (Ohms): 107-143
Temperature: 100°C
Resistance (Ohms): 64-86
Temperature: 150°C
Resistance (Ohms): 23-31

- Is the value correct?
YES: Proceed to step 7
NO: Proceed to step 8





7. Checking for a short-circuit
- Check the cable between the transmission connector terminal 12 and the Transmission Control Module (TCM) #A14 (#A14) for a short-circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 13





8. Replacing component
- Preparation:
Ignition OFF
- Try a new oil temperature sensor, refer to replacement. Service and Repair
- Then continue with step 13





9. Checking wiring and connections
- Check the cable between the oil temperature sensor and TCM #A14 for an intermittent short-circuit to ground according to step 3 of checking for intermittent faults. Checking For Intermittent Faults
- Then continue with step 10
10. Checking the transmission
- Preparation:
Ignition OFF
Reinstall the transmission connector and the Air Cleaner ACL housing
- The DTC may have been caused by the transmission being subjected to high loads and high temperatures.
- It is therefore important to change the oil and check the operation of the transmission.
Change oil.
Test drive car according to Test Drive Form. Test Drive Form
- Does the transmission have any mechanical faults?
YES: Proceed to step 12
NO: Proceed to step 11
11. Fault-tracing information
- Transmission is OK.
- Fault corrected
12. Repairing mechanical faults
- Mechanical malfunction refer to Symptom Tables for corrective action. Symptom Related Diagnostic Procedures
- If the transmission oil has not already been changed during corrective action, replace the oil.
- Fault corrected





13. Verification
- After repairs have been completed they must be verified as follows to ensure that the fault has been eliminated
- Preparation:
Ignition OFF
Reconnect connectors, reinstall components etc.
Ignition ON
Select scrolling values
Read off transmission oil temperature.
- Check that the transmission oil temperature is within bounds.
- Compare with the temperature of the transmission itself.
- Is the oil temperature within bounds?
YES: Fault corrected
NO: Proceed to step 14
14. 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 step 1