DTC Troubleshooting: P0122
DTC P0122: TP Sensor A Circuit Low Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0122 TP Sensor A 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.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
TP SENSOR A
Less than 0.3
V
    

Do the current condition(s) match the threshold?

     
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 throttle body and the PCM.?
2.
Determine possible failure area (VCC5 line, THL1 line):

Determine possible failure area (VCC5 line, THL1 line)
?1.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0122 TP Sensor A Circuit Low Voltage
     
P0222 TP Sensor B Circuit Low Voltage
      

Are DTC P0122 and P0222 indicated at the same time?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Go to step 3.
3.
Shorted wire check (THL1 line):

Shorted wire check (THL1 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
 
PCM connector B (51P): disconnected
 
Throttle body 6P connector: disconnected
Test circuit
THL1
Test point 1
Throttle body 6P connector No. 6 (RED)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the THL1 wire between the PCM (B31) and the throttle body, then do the repair verification.
     
NO
     
     
     
The THL1 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.
4.
Determine possible failure area (VCC5 line, throttle body):

Determine possible failure area (VCC5 line, throttle body)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

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

?4.
Measure the voltage between test points 1 and 2.
Test condition
ON mode
 
Throttle body 6P connector: disconnected
Test circuit
VCC5
Test point 1
Throttle body 6P connector No. 5 (BLU)
Test point 2
Body ground


Is there about 5.0 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 5.
5.
Open wire check (VCC5 line):

Open wire check (VCC5 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
 
Throttle body 6P connector: disconnected
 
PCM connector B (51P): disconnected
Test circuit
VCC5
Test point 1
Throttle body 6P connector No. 5 (BLU)
Test point 2
PCM connector B (51P) No. 44 (BLU)


Is there continuity?

     
YES
     
     
     
The VCC5 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.
     
NO
     
     
     
Repair an open in the VCC5 wire between the PCM (B44) and the throttle body, then do the repair verification.
Repair verification:

?1.
Press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?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.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0122 TP Sensor A Circuit Low Voltage
     


Is DTC P0122 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at the throttle body and the PCM. If the PCM was updated, substitute a known-good PCM, then recheck. If the PCM was substituted, go to step 1.
     
NO
     
     
     
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.?