DTC 33 Front Vehicle Speed Sensor
WARNING: This page is about a different variant/trim than selected.
DIAGNOSIS:
- The vehicle speed signal is abnormal.
- The circuit in combination meter is faulty.
- The harness connector between TCM and vehicle speed sensor is in short or open.
TROUBLE SYMPTOM:
- Erroneous idling.
- Engine stalls.
- Poor driving performance.
WIRING DIAGRAM:
DIAGNOSTIC PROCEDURE CHART
| Step | Check | Yes | No |
|---|---|---|---|
1 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION.
|
Is the resistance less than 1 Ω? | Go to step 2. | Repair the open circuit in harness between TCM and transmission connector. |
| 2 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Measure the resistance of harness between TCM and transmission connector. Connector & terminal (B55) No. 21 - (B11) No. 18: |
Is the resistance less than 1 Ω? | Go to step 3. | Repair the open circuit in harness between TCM and transmission connector, and poor contact in coupling connector. |
| 3 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Measure the resistance of harness between TCM and transmission connector. Connector & terminal (B55) No. 21 - Chassis ground: |
Is the resistance more than 1 MΩ? | Go to step 4. | Repair the short circuit in harness between TCM and transmission connector. |
| 4 CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION. Measure the resistance of harness between TCM and transmission connector. Connector & terminal (B55) No. 5 - Chassis ground: |
Is the resistance more than 1 MΩ? | Go to step 5. | Repair the short circuit in harness between TCM and transmission connector, and poor contact in coupling connector. |
| 5 CHECK FRONT VEHICLE SPEED SENSOR. Measure the resistance between transmission connector receptacle's terminals. Connector & terminal (T4) No. 17 - No. 18: |
Is the resistance 450 - 650 Ω? | Go to step 6. | Replace the front vehicle speed sensor. < Ref. to FRONT VEHICLE SPEED SENSOR . > |
| 6 PREPARE OSCILLOSCOPE. | Do you have an oscilloscope? | Go to step 9. | Go to step 7. |
| 7 PREPARE SUBARU SELECT MONITOR. | Do you have a Subaru Select Monitor? | Go to step 10. | Go to step 8. |
8 CHECK INPUT SIGNAL FOR TCM.
|
Is the voltage more than AC 1 V? | Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact or harness may be the cause. Repair the harness or connector in the front vehicle speed sensor circuit. | Go to step 11. |
9 CHECK FRONT VEHICLE SPEED SENSOR USING OSCILLOSCOPE.
|
Is the voltage more than AC 4 V? | Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor contact or harness may be the cause. Repair the harness or connector in front vehicle speed sensor circuit. | Go to step 11. |
10 CHECK INPUT SIGNAL FOR TCM USING SUBARU SELECT MONITOR.
|
Does the speedometer indication increase as Subaru Select Monitor data increases? | Even if the AT OIL TEMP warning light blinks, the circuit has returned to a normal condition at this time. A temporary poor connector or harness may be the cause. Repair the harness or connector in front vehicle speed sensor circuit. | Go to step 11. |
| 11 CHECK POOR CONTACT. | Is there poor contact in front vehicle speed sensor circuit? | Repair the poor contact. | Replace the TCM. < Ref. to TRANSMISSION CONTROL MODULE (TCM) . > |