DTC Troubleshooting: P2627, P2630
DTC P2627: Rear A/F Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage
DTC P2630: Front A/F Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
Information marked with an asterisk (*) applies to the front bank (Bank 2).

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2627 Rear A/F Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage
      
P2630 Front A/F Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage
     

1.
Problem verification:

Problem verification
?1.
Press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle for 2 minutes.

?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2627 Rear A/F Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage
      
P2630 Front A/F Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage
     

Is DTC P2627 and/or P2630* indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM.?
2.
Shorted wire check (VLBLB1 line (VLBLB2 line)):

Shorted wire check (VLBLB1 line (VLBLB2 line))
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.

?4.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
PCM connector C (51P): disconnected
Test circuit
VLBLB1 (VLBLB2)*
Test point 1
PCM connector C (51P) No. 24 (WHT)
PCM connector C (51P) No. 27 (LT BLU)*
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
The VLBLB1 (VLBLB2)* wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
3.
Shorted wire check (VLBLB1 line (VLBLB2 line)*):

Shorted wire check (VLBLB1 line (VLBLB2 line)*)
?1.
Disconnect the following connector.

?2.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
A/F sensor (Sensor 1) 8P connector: disconnected
PCM connector C (51P): disconnected
Test circuit
VLBLB1 (VLBLB2)*
Test point 1
PCM connector C (51P) No. 24 (WHT)
PCM connector C (51P) No. 27 (LT BLU)*
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the VLBLB1 (VLBLB2)* wire between the PCM (C24 (C27)*) and the A/F sensor (Sensor 1), then do the repair verification.
     
NO
     
     
     
The VLBLB1 (VLBLB2)* wire is OK. Replace the A/F sensor (Sensor 1), then do the repair verification.
Repair verification (OBD STATUS check):

?1.
Reconnect all connectors.

?2.
Exit the SCS mode with the HDS.


?3.
Press the engine start/stop button to select the ON mode.

?4.
Reset the PCM with the HDS.


?5.
Do the PCM idle learn procedure.

?6.
Monitor the OBD STATUS for DTC P2627 and/or P2630* in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P2627 Rear A/F Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage
  
P2630 Front A/F Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage
 


Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?

     
PASSED (P2627)
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting. ?
     
PASSED (P2630)
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting. ?
     
FAILED (P2627)
     
     
     
Go to step 1 and recheck.
     
FAILED (P2630)
     
     
     
Go to step 1 and recheck.
     
NOT COMPLETED
     
     
     
Keep idling until a result comes on.