Signal Too Low

SPECIAL TOOLS
Volvo Scan Tool No. 998 8686, or equivalent

SIGNAL TOO LOW
1. Status message

NOTE: To get the correct status message carry out the following before reading the diagnostic trouble code (DTC):

- Preparation:
Ignition ON.
Set mode selector to E
Wait approx. 30 seconds
Set mode selector to S
Wait approx. 30 seconds.
- Does the Volvo Scan Tool (ST) display PERMANENT FAULT?
YES: Proceed to step 2
NO: Proceed to step 10





2. Checking the driving mode selector controls
- Preparation:
Ignition OFF.
- Remove mode selector from center console.
- Check that the mode selector control moves easily and does not stick.
- Take special care that the W button does not stick in the depressed position.
- Shake the driving mode selector and check there are no loose parts in the switch.
- Is the mode selector OK?
YES: Proceed to step 4
NO: Proceed to step 3





3. Replacing mode selector
- Preparation:
Ignition OFF.
Mode selector removed
- Try a new mode selector.
- Then continue with step 8





4. Checking the driving mode selector's resistance
- Preparation:
Ignition OFF
Disconnect mode selector
- Connect an ohmmeter between the driving mode selector connector terminal:
3 and 5 with the mode selector in position E
2 and 5 with the mode selector in position S
2 and 3 with the W button up.
- The ohmmeter should read infinite resistance for all readings.
- If reading is OK:
Proceed to step 5
- If reading is incorrect:
Proceed to step 3





5. Checking signal wiring MS1
- Preparation:
Ignition OFF
Connect the driving mode selector
Ignition ON
Read off mode selector sensor signal MS1
Set mode selector to E.
- Does the mode selector sensor signal MS1 display HIGH?
YES: Proceed to step 6
NO: Proceed to step 7





6. Checking for a short-circuit
- Preparation:
Ignition ON
Mode selector connected
- Check the cable between the mode selector connector terminal 2 and transmission control module (TCM) #B16 for an intermittent open-circuit according to step 3 of checking for permanent faults. Checking For Permanent Faults.
- Then continue with step 8





7. Checking for a short-circuit
- Preparation:
Ignition ON
Mode selector connected
- Check the cable between the mode selector connector terminal 3 and TCM #B17 for a short-circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 8





8. Verification
- After repairs have been completed they must be verified as follows to ensure that the fault has been eliminated
- Preparation:
Ignition OFF.
Reconnect the connectors, reinstall components etc.
Ignition ON.
Select scrolling values.
Read off the driving mode selector position.
- Check positions E, S and W.
- Are all positions OK?
YES: Fault corrected
NO: Proceed to step 9
9. 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





10. Intermittent fault
- Check W button does not stick down in the depressed position and operates smoothly without catching.
- Check the cable between the mode selector connector terminal 2 and TCM #B16 for an intermittent short-circuit to ground according to step 3 of checking for intermittent faults. Checking For Intermittent Faults
- Check the cable between the driving mode selector connector terminal 3 and transmission control module (TCM) #B17 for an intermittent short-circuit to ground according to step 3 of checking for intermittent faults. Checking For Intermittent Faults
- Then continue with step 11
11. 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 step 1
NO: Operation done