DTC P0123:00 [MZR 1.6]

id0102h3701900

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 is switched to ON, the PCM determines that the TP sensor No.1 circuit has a malfunction.

Diagnostic support note

•  This is a continuous monitor (CCM).

•  The check engine light illuminates if the PCM detects the above malfunction condition in the first drive cycle.

•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.

•  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 2AL

•  TP sensor No.1 power supply circuit and signal circuit are shorted to each other

•  Open circuit in wiring harness between the following terminals:

―  Throttle body terminal E—PCM terminal 2AU

―  Throttle body terminal F—PCM terminal 2AL

―  Throttle body terminal C—PCM terminal 2AP

•  TP sensor No.1 malfunction

•  PCM malfunction

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 is switched to ON, the PCM determines that the TP sensor No.1 circuit has a malfunction. Diagnostic support note • This is a continuous monitor (CCM). • The check engine light illuminates if the PCM detects the above malfunction condition in the first drive cycle. • FREEZE FRAME DATA (Mode 2)/Snapshot data is available. • 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 2AL • TP sensor No.1 power supply circuit and signal circuit are shorted to each other • Open circuit in wiring harness between the following terminals: ― Throttle body terminal E—PCM terminal 2AU ― Throttle body terminal F—PCM terminal 2AL ― Throttle body terminal C—PCM terminal 2AP • TP sensor No.1 malfunction • PCM malfunction

Diagnostic Procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data on 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.
2		No	Go to the next step.
3	INSPECT THROTTLE BODY CONNECTOR CONDITION • Switch the ignition 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 9.
3		No	Go to the next step.
4	INSPECT PCM CONNECTOR CONDITION • 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 9.
4		No	Go to the next step.
5	INSPECT TP SENSOR NO.1 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Verify that the throttle body and PCM connectors are disconnected. • Switch the ignition ON (engine off). Note • Another DTC may be stored by the PCM detecting an open circuit. • Measure the voltage at the throttle body terminal F (wiring harness-side). • Is the voltage 0 V?	Yes	Go to the next step.
5		No	Refer to the wiring diagram and verify whether or not there is a common connector between throttle body terminal F and PCM terminal 2AL. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to power supply. Go to Step 9.
6	INSPECT TP SENSOR NO.1 POWER SUPPLY CIRCUIT AND SIGNAL CIRCUIT FOR SHORT TO EACH OTHER • Verify that the throttle body and PCM connectors are disconnected. • Switch the ignition off. • Inspect for continuity between throttle body terminals E and F (wiring harness-side). • Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Throttle body terminal E—PCM terminal 2AU • Throttle body terminal F—PCM terminal 2AL If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to each other. Go to Step 9.
6		No	Go to the next step.
7	INSPECT TP SENSOR NO.1 CIRCUIT FOR OPEN CIRCUIT • Verify that the throttle body and PCM connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ― Throttle body terminal E—PCM terminal 2AU ― Throttle body terminal F—PCM terminal 2AL ― Throttle body terminal C—PCM terminal 2AP • Is there continuity?	Yes	Go to the next step.
7		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • Throttle body terminal E—PCM terminal 2AU • Throttle body terminal F—PCM terminal 2AL • Throttle body terminal C—PCM terminal 2AP If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to Step 9.
8	INSPECT TP SENSOR NO.1 • Reconnect all disconnected connectors. • Inspect the TP sensor No.1. (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 1.6].) • Is there any malfunction?	Yes	Replace the throttle body, then go to the next step. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.6].)
8		No	Go to the next step.
9	VERIFY DTC TROUBLESHOOTING COMPLETED • Always reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [MZR 1.6].) • Start the engine. • Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.6].) • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.6].) Go to the next step.
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZR 1.6].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 1.6].)
10		No	DTC troubleshooting completed.