DTC Troubleshooting: P0123
DTC P0123: TP Sensor A Circuit High Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0123 TP Sensor A Circuit High Voltage
   

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0123 TP Sensor A Circuit High Voltage
   

Is DTC P0123 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 throttle body 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.?
2.
Determine possible failure area (SG THL line, others):

Determine possible failure area (SG THL line, others)
?1.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0123 TP Sensor A Circuit High Voltage
   
P0223 TP Sensor B Circuit High Voltage
    

Are DTC P0123 and P0223 indicated at the same time?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Go to step 3.
3.
Determine possible failure area (throttle body, others):

Determine possible failure area (throttle body, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Throttle body 6P connector

?3.
Turn the vehicle to the ON mode.

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


Is there about 5.0 V?

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

Open wire check (THL1 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 No. 1 (96P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Throttle body 6P connector: disconnected
 
PCM connector No. 1 (96P): disconnected
Test point 1
Throttle body 6P connector (female terminals) No. 6:
Test point 2
PCM connector No. 1 (96P) No. 89


Is there continuity?

     
YES
     
     
     
The THL1 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 P0123 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the THL1 wire between PCM connector No. 1 terminal No. 89 and the throttle body.?
5.
Open wire check (SG THL line):

Open wire check (SG THL 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 connectors.
PCM connector No. 1 (96P)
Throttle body 6P connector

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector No. 1 (96P): disconnected
 
Throttle body 6P connector: disconnected
Test point 1
Throttle body 6P connector (female terminals) No. 3:
Test point 2
PCM connector No. 1 (96P) No. 23


Is there continuity?

     
YES
     
     
     
The SG THL 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 P0123 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the SG THL wire between PCM connector No. 1 terminal No. 23 and the throttle body.?