DTC P0137

DTC P0137  : Secondary HO2S (Sensor 2) Circuit Low Voltage

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

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Enter the maintenance mode, then start the engine .

   -4. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

   -5. Monitor the OBD STATUS for DTC P0137 in the DTCs MENU with the HDS.

   DTC Description	OBD STATUS
   P0137 Secondary HO2S (Sensor 2) Circuit Low Voltage

   Does the HDS indicate FAILED?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   If the HDS indicates PASSED, there is an intermittent failure and the system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) 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 . If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-4 and recheck.

2. Determine possible failure area (secondary HO2S (Sensor 2), others)

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

   -2. Disconnect the following connector.

   Secondary HO2S (Sensor 2) 4P connector

   -3. Turn the vehicle to the ON mode.

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

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   HO2S S2	Less than 0.15	V

   Do the current condition (s) match the threshold?

   YES 

   Go to step 3.

   NO 

   Replace the secondary HO2S (Sensor 2) .

3. Determine possible failure area (short in SO2 line, short in SO2SG/SO2_SG line)

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

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

   Test condition	Vehicle OFF (LOCK) mode
   	Secondary HO2S (Sensor 2) 4P connector: disconnected
   Test point 1	Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1:
   Test point 2	Body ground

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

   Is there 1 MΩ or more?

   YES 

   Go to step 5.

   NO 

   Go to step 4.

4. Shorted wire check (SO2 line)

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

   -2. Disconnect the following connector.

   PCM connector A (50P)

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Secondary HO2S (Sensor 2) 4P connector: disconnected
   	PCM connector A (50P) : disconnected
   Test point 1	Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1:
   Test point 2	Body ground

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

   Is there 1 MΩ or more?

   YES 

   The SO2 wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM .

   NO 

   Repair a short in the SO2 wire between the PCM (A47) and the secondary HO2S (Sensor 2).

5. Shorted wire check (SO2SG/SO2_SG line)

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

   -2. Disconnect the following connector.

   PCM connector A (50P)

   -3. Measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Secondary HO2S (Sensor 2) 4P connector: disconnected
   	PCM connector A (50P) : disconnected
   Test point 1	Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 2:
   Test point 2	Body ground

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

   Is there 1 MΩ or more?

   YES 

   The SO2SG/SO2_SG wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM .

   NO 

   Repair a short in the SO2SG/SO2_SG wire between the PCM (A48) and the secondary HO2S (Sensor 2).