DTC P0721 (L15B7/L15BA/L15BY) (19-21)

DTC P0721  : Output Shaft (Countershaft) Speed Sensor Out of Range

NOTE:  Before you troubleshoot, review the general troubleshooting information .

DTC (PGM-FI)

1. Problem verification

   -1. Start the engine.

   -2. Hold the engine speed at 3, 000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

   -3. Test-drive the vehicle several minutes.

   -4. Check the parameter (s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   C SHAFT SPD

   Is any vehicle speed indicated?

   YES 

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the output shaft (countershaft) speed sensor and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot .

   NO 

   The failure is duplicated. Go to step 2.

2. Determine possible failure area (VCC1 line or SG1 line, others)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Output shaft (countershaft) speed sensor 3P connector

   -3. Turn the vehicle to the ON mode.

   -4. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Output shaft (countershaft) speed sensor 3P connector: disconnected
   Test point 1	Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 1:
   Test point 2	Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 3:

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5.0 V?

   YES 

   Go to step 4.

   NO 

   Go to step 3.

3. Open wire check (VCC1 line)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Output shaft (countershaft) speed sensor 3P connector: disconnected
   Test point 1	Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 3:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5.0 V?

   YES 

   The VCC1 wire is OK. Repair an open in the SG1 wire between the PCM (E71) and the output shaft (countershaft) speed sensor.

   NO 

   Repair an open in the VCC1 wire between the PCM (E70) and the output shaft (countershaft) speed sensor.

4. Determine possible failure area (output shaft (countershaft) speed sensor, others)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Output shaft (countershaft) speed sensor 3P connector: disconnected
   Test point 1	Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 2:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there about 5.0 V ?

   YES 

   Replace the output shaft (countershaft) speed sensor .

   NO 

   Go to step 5.

5. Shorted wire check (NC line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Jump the SCS line with the HDS, and wait more than 1 minute.

   -3. Disconnect the following connector.

   PCM connector E (80P)

   -4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Output shaft (countershaft) speed sensor 3P connector: disconnected
   	PCM connector E (80P): disconnected
   Test point 1	PCM connector E (80P) No. 66
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short in the NC wire between the PCM (E66) and the output shaft (countershaft) speed sensor.

   NO 

   The NC wire is not shorted. Go to step 6.

6. Open wire check (NC line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Output shaft (countershaft) speed sensor 3P connector: disconnected
   	PCM connector E (80P): disconnected
   Test point 1	Output shaft (countershaft) speed sensor 3P connector (female terminals) No. 2:
   Test point 2	PCM connector E (80P) No. 66

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The NC wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC P0721 goes away and the PCM was substituted, replace the original PCM .

   NO 

   Repair an open in the NC wire between the PCM (E66) and the output shaft (countershaft) speed sensor.