DTC Troubleshooting: P2252, P2255
DTC P2252: Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage
DTC P2255: Front A/F Sensor (Bank 2, Sensor 1) VS 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
P2252 Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage
      
P2255 Front A/F Sensor (Bank 2, Sensor 1) VS 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
P2252 Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage
     
P2255 Front A/F Sensor (Bank 2, Sensor 1) VS Circuit Low Voltage
     

Is DTC P2252 and/or P2255* 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), the PGM-FI subrelay, and the PCM.?
2.
Shorted wire check (VSB1 (VSB2)* line):

Shorted wire check (VSB1 (VSB2)* 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 connectors.

?4.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
 
A/F sensor (Sensor 1) 6P connector: disconnected
 
PCM connector C (51P): disconnected
Test circuit
VSB1 (VSB2)*
Test point 1
PCM connector C (51P) No. 25 (LT GRN)
 
PCM connector C (51P) No. 28 (WHT)*
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the VSB1 (VSB2)* wire between the PCM (C25 (C28)*) and the A/F sensor (Sensor 1), then do the repair verification.
     
NO
     
     
     
The VSB1 (VSB2)* wire is OK. Go to step 3.
3.
PCM internal circuit check:

PCM internal circuit check
?1.
Exit the SCS mode with the HDS.


?2.
Reconnect PCM connector C (51P).

?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.
Measure the voltage between test points 1 and 2.
Test condition
Engine running
 
A/F sensor (Sensor 1) 6P connector: disconnected
Test circuit
VSB1 (VSB2)*
Test point 1
Rear A/F sensor (Bank 1, Sensor 1) 6P connector No. 6 (LT GRN)
 
Front A/F sensor (Bank 2, Sensor 1) 6P connector No. 6 (WHT)*
Test point 2
Body ground


Is there about 0.2 V or less?

     
YES
     
     
     
Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
The PCM internal circuit is OK. Replace the A/F sensor (Sensor 1), then do the repair verification.
Repair verification (OBD STATUS check):

?1.
Open the SCS line with the HDS.


?2.
Press the engine start/stop button to select the OFF mode.

?3.
Reconnect all connectors.

?4.
Press the engine start/stop button to select the ON mode.

?5.
Reset the PCM with the HDS.


?6.
Do the PCM idle learn procedure.

?7.
Monitor the OBD STATUS for DTC P2252 and/or P2255* in the DTCs MENU with the HDS.
DTC Description
OBD Status
P2252 Rear A/F Sensor (Bank 1, Sensor 1) VS Circuit Low Voltage
 
P2255 Front A/F Sensor (Bank 2, Sensor 1) VS Circuit Low Voltage
 


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

     
PASSED (P2252)
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?
     
PASSED (P2255)
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?
     
FAILED (P2252)
     
     
     
Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.
     
FAILED (P2255)
     
     
     
Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.
     
NOT COMPLETED
     
     
     
Keep idling until a result comes on.