DTC Troubleshooting: P0843
DTC P0843: Transmission Fluid Pressure Sensor/Switch "A" Circuit High
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information.
This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0843 Transmission Fluid Pressure Sensor/Switch "A" Circuit High
      

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.
Clear the DTC with the HDS.


?3.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
Driven Pulley Pressure Sensor(V)
More than 4.84
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 between the CVT driven pulley pressure sensor and the PCM.?
2.
Determine possible failure area (PDN line, CVT driven pulley pressure sensor, others):

Determine possible failure area (PDN line, CVT driven pulley pressure sensor, 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.
Connect terminals A and B with a jumper wire.
Terminal A
CVT driven pulley pressure sensor 3P connector No. 1 (GRY)
Terminal B
CVT driven pulley pressure sensor 3P connector No. 2 (BLU)


?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
Driven Pulley Pressure Sensor(V)
More than 4.84
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Go to step 4.
3.
Open wire check (PDN line):

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

?2.
Remove the jumper wire.

?3.
Jump the SCS line with the HDS.


?4.
Disconnect the following connector.

?5.
Check for continuity between test points 1 and 2.
Test condition
Ignition switch LOCK (0), or OFF mode
 
CVT driven pulley pressure sensor 3P connector: disconnected
 
PCM connector C (51P): disconnected
Test circuit
PDN
Test point 1
CVT driven pulley pressure sensor 3P connector No. 2 (BLU)
Test point 2
PCM connector C (51P) No. 49 (BLU)


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Repair an open in the PDN wire between the CVT driven pulley pressure sensor and the PCM, then do the repair verification.
4.
CVT driven pulley pressure sensor check:

CVT driven pulley pressure sensor check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Remove the jumper wire.

?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
Ignition switch ON (II), or ON mode
 
CVT driven pulley pressure sensor 3P connector: disconnected
Test circuit
VCC2, SG2
Test point 1
CVT driven pulley pressure sensor 3P connector No. 1 (GRY)
Test point 2
CVT driven pulley pressure sensor 3P connector No. 3 (TAN)


Is there about 5 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 5.
5.
Power supply circuit check:

Power supply circuit check
?1.
Measure the voltage between test points 1 and 2.
Test condition
Ignition switch ON (II), or ON mode
 
CVT driven pulley pressure sensor 3P connector: disconnected
Test circuit
VCC2
Test point 1
CVT driven pulley pressure sensor 3P connector No. 3 (TAN)
Test point 2
Body ground


Is there about 5 V?

     
YES
     
     
     
Repair an open in the SG2 wire between the CVT driven pulley pressure sensor and the PCM, then do the repair verification.
     
NO
     
     
     
Repair an open in the VCC2 wire between the CVT driven pulley pressure sensor and the PCM, then do the repair verification.
Repair verification (OBD STATUS check):

?1.
Reconnect all connectors.

?2.
Exit the SCS mode with the HDS.


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

?4.
Clear the DTC with the HDS.


?5.
Start the engine in P, and wait for at least 10 seconds. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, then restart the engine in P, and wait for at least 10 seconds.

?6.
Monitor the OBD STATUS for P0843 in the DTCs MENU with the HDS.
DTC Description
OBD Status
P0843 Transmission Fluid Pressure Sensor/Switch "A" Circuit High
  


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

     
PASSED
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Troubleshooting is incomplete. Check for poor connections or loose terminals between the CVT driven pulley pressure sensor and the PCM, then go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, and check the OBD STATUS again.
     
NOT COMPLETED
     
     
     
Repair verification is incomplete. Meet the test condition, and check the OBD STATUS again.