Signal Missing
SPECIAL TOOLS
Test box tool No. 981 3190, or equivalent
Volvo scan tool No. 998 8686, or equivalent
SIGNAL MISSING
1. Checking transmission speed signal
NOTE: An alternative to the following method is to drive the car on the road.
- Preparation:
Ignition OFF
Raise car so that front wheels rotate freely.
Engine idling.
Select scrolling values
Read off transmission input speed.
Move the gear selector to position D so the front wheels begin to rotate.
- Check that the transmission input speed is updated.
- The transmission input speed should increase with engine speed.
NOTE:
- When the rear wheels are stationary and the front wheels rotate Diagnostic Trouble Codes (DTCs) may can be stored in the ABS system.
- Erase any DTCs stored in the ABS system after fault-tracing.
- Refer to Brakes and Traction Control
- Ensure that the front wheels are not rotating when the gear shift lever is moved
- Is the transmission input speed OK?
YES: Proceed to step 19
NO: Proceed to step 2
2. Connecting the test box
- Preparation:
Ignition OFF
- Connect the test box and check ground terminals. Connecting the Test Box
- Then continue with step 3
3. Checking transmission speed sensor circuit
- Preparation:
Ignition OFF
Transmission Control Module (TCM) disconnected.
- Use an ohmmeter to measure between #1 (#A1 ) and #2 (#A2) on the test box.
- The ohmmeter should read 300-600 Ohms
- If reading is OK:
Proceed to step 13
- If reading is incorrect:
Proceed to step 4
4. Checking transmission speed sensor resistance
- Preparation:
Ignition OFF
Remove the Air Cleaner (ACL) housing to access the transmission connector.
Disconnect the transmission connector.
TCM disconnected.
- Connect an ohmmeter between the transmission connector terminals 16 and 17 (transmission speed sensor side)
- The ohmmeter should read 300-600 Ohms
- If reading is OK:
Proceed to step 6
- If reading is incorrect:
Proceed to step 5
5. Checking for open-circuit and replacement of component
- Preparation:
Ignition OFF
- Check the cables between the transmission speed sensor and transmission connector terminal 16 and 17 for:
An open-circuit according to step 2 of checking for permanent faults. Checking For Permanent Faults
A short circuit to each other.
- If the wiring is OK, try a new transmission speed sensor, refer to replacement. Service and Repair
- Then continue with step 17
6. Checking resistance in signal (+) cable
- Preparation:
Ignition OFF
Disconnect transmission connector.
TCM disconnected.
- Connect an ohmmeter between the transmission connector terminal 16 (TCM side) and #1 (#A1) on the test box.
- The ohmmeter should read approx. 0 Ohms
- If reading is OK:
Proceed to step 8
- If reading is incorrect:
Proceed to step 7
7. Checking for an open-circuit
- Check cable between transmission connector terminal 16 and control module #A1 for an open-circuit according to step 2 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
8. Checking resistance in signal (-) cable
- Preparation:
Ignition OFF
Disconnect transmission connector.
TCM disconnected.
- Connect an ohmmeter between the transmission connector terminal 17 (TCM side) and #2 (#A2) on the test box.
- The ohmmeter should read approx. 0 Ohms
- If reading is OK:
Proceed to step 10
- If reading is incorrect:
Proceed to step 9
9. Checking for an open-circuit
- Check cable between transmission connector terminal 17 and control module #A2 for an open-circuit in according to step 2 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
10. Checking signal wiring resistance
- Preparation:
Ignition OFF
Disconnect transmission connector.
TCM disconnected
- Use an ohmmeter to measure between #1 (#A1) and #2 (#A2) on the test box.
- The ohmmeter should read infinite resistance
- If reading is OK:
Proceed to step 11
- If reading is incorrect:
Proceed to step 12
11. Checking for contact resistance and oxidation.
- Preparation:
Ignition OFF
- The DTC was set because of poor contact in the TCM and transmission connectors.
- Check connectors for contact resistance and oxidation and remedy according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
12. Checking for a short-circuit
- Check the cable between the transmission connector terminal 16 and TCM #A1 for short circuit to cable between the transmission connector terminal 17 and TCM #A2.
- Then continue with step 17
13 Checking the signal wiring
- Preparation:
Ignition OFF
Test box connected
Connect TCM
Ignition ON
- Use a voltmeter between #1 (#A1) and #20 (#A20) on the test box.
- The voltmeter should register approx. 2.5 volts
- If reading is OK:
Proceed to step 14
- If value is lower:
Proceed to step 15
- If value is higher:
Proceed to step 16
14. Checking for contact resistance and oxidation.
- Preparation:
Ignition OFF
- The DTC was caused by poor contact in the TCM connector.
- Check transmission and control module connectors for contact resistance and oxidation and remedy according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
15. Checking for a short-circuit
- Check cables between transmission speed sensor and TCM #A1 and #A2 for short circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
16 Checking for a short-circuit
- Check cables between transmission speed sensor and TCM #A1 and #A2 for a short-circuit to supply voltage according to step 3 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 17
17. Verification
- After carrying out the repair, check that the fault has been remedied.
- Carry out the following.
NOTE: An alternative to the following method is to drive the car on the road.
- Preparation:
Ignition OFF
Reconnect connectors, reinstall components etc.
Raise car so that front wheels rotate freely.
Engine idling.
Select scrolling values
Read off transmission input speed.
Move the gear selector to position D so the front wheels begin to rotate.
- Check that the transmission input speed is update.
- The transmission input speed should increase with engine speed.
NOTE:
- When the rear wheels are stationary and the front wheels rotate DTCs may can be stored in the ABS system
- Erase any DTCs stored in the ABS system after fault-tracing.
- Refer to Brakes and Traction Control
- Ensure that the front wheels are not rotating when the gear shift lever is moved
- Is the transmission input speed OK?
YES: Fault corrected
NO: Proceed to step 18
18 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
19. Intermittent fault
- Preparation:
Ignition OFF
- Check transmission connector and control module connector for:
Loose connections according to step 5 of checking for intermittent faults. Checking For Intermittent Faults
Contact resistance and oxidation according to step 6 of checking for permanent faults. Checking For Permanent Faults
- Check cables between transmission speed sensor and TCM #A1 and #A2 for:
An intermittent open-circuit according to step 2 of checking for intermittent faults. Checking For Intermittent Faults
An intermittent short-circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
An intermittent short-circuit to supply voltage according to step 4 of checking for permanent faults. Checking For Permanent Faults
- Check cables between the transmission speed sensor and TCM #A1 and #A2 for an intermittent short-circuit to each other.
- Then continue with step 20
20. 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