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DTC P0721: Output Speed Sensor (OSS) Circuit Range/Performance: Troubleshooting

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2008 Suzuki Reno, 2008 Suzuki Forenza, 2007 Suzuki Reno, 2007 Suzuki Forenza, and 2006 Suzuki Reno. However, it is still accessible from the selected car via links, so may be relevant.
TROUBLESHOOTING REFERENCE CHART

Step Action Value(s) Yes No
1 Perform an On-Board Diagnostic (OBD II) System Check.
Is the check completed?		 - Go to Step 2 Go to ON-BOARD DIAGNOSTIC (OBD II) SYSTEM CHECK
2
  1. Install the scan tool.
  2. Turn the ignition ON and record then clear DTC(s), then turn the ignition OFF.
  3. Raise and support the drive wheels, then start the engine.
  4. Gear position is D and observe the output speed on the scan tool.

Is the speed within the values shown?		 190 - 9,762 RPM Go to DIAGNOSTIC AIDS Go to Step 3
3
  1. Turn the ignition OFF.
  2. Disconnect the transaxle wiring connector.
  3. Measure the resistance between terminals 1 and 2 of the transaxle wiring connector.

Is the resistance within the values shown?		 ∞ Ω Go to Step 9 Go to Step 4
4
  1. Remove the oil pan.
  2. Disconnect the output speed sensor wiring connector.
  3. Measure the resistance between terminal 1 of the output speed sensor wiring connector and terminal 1 of the transaxle wiring connector.
  4. Measure the resistance between terminal 2 of the output speed sensor wiring connector and terminal 2 of the transaxle wiring connector.

Is the resistance within the values shown?		 0 Ω Go to Step 6 Go to Step 5
5 Repair the malfunctioning terminals as necessary.
Is the action complete?		 - System OK -
6
  1. Turn the ignition ON.
  2. Measure the voltage of terminal 1.
  3. Measure the voltage of terminal 2.

Is the voltage within the values shown?		 11 - 14 V Go to Step 7 Go to Step 8
7 Repair the malfunctioning terminals as necessary.
Is the action complete?		 - System OK -
8 Replace the input speed sensor.
Is the action complete?		 - System OK -
9
  1. Disconnect the transaxle wiring connector and TCM connector.
  2. Measure the resistance between terminal 1 of the transaxle wiring connector and terminal B10 of the TCM wiring connector.
  3. Measure the resistance between terminal 2 of the transaxle wiring connector and terminal B5 of the TCM wiring connector.

Is the resistance within the values shown?		 0 Ω Go to Step 11 Go to Step 10
10 Repair the malfunctioning terminals as necessary.
Is the action complete?		 - System OK -
11
  1. Turn the ignition ON.
  2. Measure the voltage of terminal 1.
  3. Measure the voltage of terminal 2.

Is the voltage within the values shown?		 11 - 14 V Go to Step 12 Go to Step 13
12 Repair the malfunctioning terminals as necessary.
Is the action complete?		 - System OK -
13 Replace the TCM.
Is the action complete?		 - Go to Step 14 -
14
  1. After the repair, use a scan tool "clear info" function and road test the vehicle.
  2. Review the "DTC info".

Has the last test failed or is the current DTC displayed?		 - Begin diagnosis again Repair verified exit DTC chart
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