DTC Troubleshooting: P2127
DTC P2127: APP Sensor B (TP Sensor E) 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
P2127 APP Sensor B (TP Sensor E) Circuit Low Voltage
      

1.
Problem verification:

Problem verification
?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
APP SENSOR B
Less than 0.2
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 APP sensor and the PCM.?
2.
Determine possible failure area (VCC5 line, others):

Determine possible failure area (VCC5 line, others)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
IG ON (II) or ON mode
 
APP sensor 6P connector: disconnected
Test circuit
VCC5, SG5
Test point 1
APP sensor 6P connector No. 1 (BRN)
Test point 2
APP sensor 6P connector No. 2 (GRN)


Is there about 5.0 V?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Go to step 6.
3.
Shorted wire check (APS2 line):

Shorted wire check (APS2 line)
?1.
Turn the ignition switch to LOCK (0), or 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
IG LOCK (0) or OFF mode
 
APP sensor 6P connector: disconnected
 
PCM connector A (51P): disconnected
Test circuit
APS2
Test point 1
APP sensor 6P connector No. 3 (WHT)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the APS2 wire between the PCM (A38) and the APP sensor, then do the repair verification.
     
NO
     
     
     
The APS2 wire is not shorted. Go to step 4.
4.
Open wire check (APS2 line):

Open wire check (APS2 line)
?1.
Connect terminals A and B with a jumper wire.
Terminal A
APP sensor 6P connector No. 3 (WHT)
Terminal B
Body ground


?2.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
APP sensor 6P connector: disconnected
 
APP sensor 6P connector No. 3: jumped to body ground
 
PCM connector A (51P): disconnected
Test circuit
APS2
Test point 1
PCM connector A (51P) No. 38 (WHT)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
The APS2 wire is OK. Go to step 5.
     
NO
     
     
     
Repair an open in the APS2 wire between the PCM (A38) and the APP sensor, then do the repair verification.
5.
PCM internal circuit check:

PCM internal circuit check
?1.
Reconnect the following connector.

?2.
Remove the jumper wire from the APP sensor 6P connector.

?3.
Connect terminals A and B with a jumper wire.
Terminal A
APP sensor 6P connector No. 1 (BRN)
Terminal B
APP sensor 6P connector No. 3 (WHT)


?4.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?5.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
APP SENSOR B
Less than 0.2
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
     
NO
     
     
     
6.
Open wire check (VCC5 line):

Open wire check (VCC5 line)
?1.
Turn the ignition switch to LOCK (0), or 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.
Connect terminals A and B with a jumper wire.
Terminal A
APP sensor 6P connector No. 1 (BRN)
Terminal B
Body ground


?5.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
APP sensor 6P connector: disconnected
 
APP sensor 6P connector No. 1: jumped to body ground
 
PCM connector A (51P): disconnected
Test circuit
VCC5
Test point 1
PCM connector A (51P) No. 40 (BRN)
Test point 2
Body ground


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 (A40) and the APP sensor, then do the repair verification.
Repair verification:

?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Turn the ignition switch to ON (II), or 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
P2127 APP Sensor B (TP Sensor E) Circuit Low Voltage
      


Is DTC P2127 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at the APP Sensor 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.?