DTC P0123:00 [ZJ, ZY]

id0102c0701900

DTC P0123:00

TP sensor No.1 circuit high input
DETECTION CONDITION
•  If the PCM detects that the TP sensor No.1 voltage is more than 4.9 V after the ignition switch is turned to the ON position, the PCM determines that the TP sensor No.1 circuit has a malfunction.
Diagnostic support note
•  This is a continuous monitor (CCM).
•  The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle.
•  FREEZE FRAME DATA is available.
•  The DTC is stored in the PCM memory.
POSSIBLE CAUSE
•  Throttle body connector or terminals malfunction
•  PCM connector or terminals malfunction
•  Short to power supply in wiring harness between throttle body terminal F and PCM terminal 2AX
•  Open circuit in wiring harness between the following terminals:
―  Throttle body terminal F and PCM terminal 2AX
―  Throttle body terminal C and PCM terminal 2AW
•  TP sensor No.1 malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
INSPECT THROTTLE BODY CONNECTOR AND TERMINALS
•  Turn the ignition switch off.
•  Disconnect the throttle body connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector or terminals, then go to Step 8.
No
Go to the next step.
4
INSPECT PCM CONNECTOR AND TERMINALS
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector or terminals, then go to Step 8.
No
Go to the next step.
5
INSPECT TP SENSOR NO.1 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Throttle body and PCM connectors are disconnected.
•  Turn the ignition switch to the ON position (engine off).
•  Measure the voltage between throttle body terminal F (wiring harness-side) and body ground.
•  Is there any voltage?
Yes
Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
No
Go to the next step.
6
INSPECT TP SENSOR NO.1 CIRCUIT FOR OPEN CIRCUIT
•  Throttle body and PCM connectors are disconnected.
•  Turn the ignition switch off.
•  Inspect for continuity between the following terminals (wiring harness-side):
―  Throttle body terminal F and PCM terminal 2AX
―  Throttle body terminal C and PCM terminal 2AW
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to Step 8.
7
INSPECT TP SENSOR NO.1
•  Reconnect throttle body and PCM connectors.
•  Inspect the TP sensor No.1.
•  Is there any malfunction?
Yes
Replace the throttle body, then go to the next step.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [ZJ, ZY].)
No
Go to the next step.
8
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine.
•  Perform the KOEO/KOER self test.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [ZJ, ZY].)
No
Go to the next step.
9
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [ZJ, ZY].)
No
DTC troubleshooting completed.