DTC P0720:00 [FN4A-EL]

id050218817700

DTC P0720:00

VSS circuit malfunction
DETECTION CONDITION
•  The PCM detects no signal from the VSS for 5 s when the following conditions are met.
―  Engine coolant temperature: 60 °C {140 °F} or more
―  Selector lever position: D or M range
―  Turbine speed: 1,500 rpm or more
Diagnostic support note
•  The MIL illuminates if the PCM detects the above malfunction condition during the first drive cycle.
•  The AT warning light illuminates if the PCM detects the above malfunction condition during the first drive cycle.
•  PENDING CODE is available.
•  FREEZE FRAME DATA is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  VSS connector or terminal malfunction
•  Open circuit in wiring harness between VSS terminal A and main relay
•  Short to GND in wiring harness between VSS terminal A and main relay
•  Short to GND in wiring harness between VSS terminal B and PCM terminal 1AX
•  Short to power supply in wiring harness between VSS terminal B and PCM terminal 1AX
•  Open circuit in wiring harness between VSS terminal C and PCM terminal 1A
•  VSS malfunction
•  PCM connector or terminal malfunction
•  Open circuit in wiring harness between VSS terminal B and PCM terminal 1AX
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA been recorded on the repair order?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT VSS CONNECTOR FOR POOR CONNECTION
•  Switch the ignition off.
•  Disconnect the VSS connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion)
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 10.
No
Go to the next step.
4
INSPECT VSS POWER CIRCUIT FOR OPEN CIRCUIT
•  Switch the ignition to ON (Engine off).
•  Measure the voltage between VSS terminal A (wiring harness-side) and body GND.
•  Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to Step 10.
5
INSPECT VSS CIRCUIT FOR SHORT TO GND
•  Switch the ignition off.
•  Inspect for continuity between the following circuits:
―  VSS terminal A (wiring harness-side) and body GND
―  VSS terminal B (wiring harness-side) and body GND
•  Is there continuity?
Yes
Repair or replace the wiring harness for a possible short to GND, then go to Step 10.
No
Go to the next step.
6
INSPECT VSS SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Switch the ignition to ON (Engine off).
•  Measure the voltage between VSS terminal B (wiring harness-side) and body GND.
•  Is the voltage B+?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 10.
No
Go to the next step.
7
INSPECT VSS
•  Inspect the VSS.
•  Is there any malfunction?
Yes
Replace the VSS, then go to Step 10.
(See VEHICLE SPEED SENSOR (VSS) REMOVAL/INSTALLATION [FN4A-EL].)
No
Go to the next step.
8
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Switch the ignition off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion)
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 10.
No
Go to the next step.
9
INSPECT VSS CIRCUIT FOR OPEN CIRCUIT
•  Switch the ignition off.
•  Inspect for continuity between the following circuits:
―  VSS terminal B (wiring harness-side) and PCM terminal 1AX (wiring harness-side)
―  VSS terminal C (wiring harness-side) and PCM terminal 1A (wiring harness-side)
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
10
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all the disconnected connectors.
•  Clear the DTC using the M-MDS.
•  Perform the following procedure to ensure that the DTC has been resolved:
1.  Start the engine.
2.  Warm-up the engine until the engine coolant temperature reaches 60 °C {140 °C} or more.
3.  Select the selector lever to D or M range.
4.  Drive the vehicle with turbine speed at 1,500 rpm or more for 5 s or more.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [FN4A-EL].)
No
Go to the next step.
11
VERIFY NO DTCs ARE PRESENT
•  Perform the “Reading DTCs Procedure”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [FN4A-EL].)
No
DTC troubleshooting completed.