DTC P0123 [13B-MSP]

DTC REFERENCE CHART

DTC P0123

TP sensor No. 1 circuit high input

DETECTION CONDITION

The PCM monitors the input voltage from the TP sensor No. 1 when the engine is running. If the input voltage is more than 4.8 V , the PCM determines that the TP sensor No. 1 circuit input voltage is high.

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

Connector or terminal malfunction
Short to power supply in wiring harness between throttle body terminal F and PCM terminal 2AK
TP sensor No. 1 malfunction
Open circuit in wiring harness between throttle body terminal C and PCM terminal 2P
PCM malfunction

G05982319

Courtesy of MAZDA MOTORS CORP.

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT THROTTLE BODY CONNECTOR FOR POOR CONNECTION 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 terminal, then go to Step 8.
3		No	Go to the next step.
4	INSPECT TP SENSOR NO. 1 SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY 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 the voltage B+ ?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 8.
4		No	Go to the next step.
5	INSPECT TP SENSOR NO. 1 Inspect the TP sensor No. 1. (See THROTTLE POSITION (TP) SENSOR INSPECTION [13B-MSP] .) Is there any malfunction?	Yes	Replace the throttle body, then go to Step 8. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [13B-MSP] .)
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion.) Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 8.
6		No	Go to the next step.
7	INSPECT TP SENSOR NO. 1 GROUND CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch off. Inspect for continuity between throttle body terminal C (wiring harness-side) and PCM terminal 2P (wiring harness-side.) Is there continuity?	Yes	Go to the next step.
7		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
8	VERIFY TROUBLESHOOTING OF DTC P0123 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Start the engine. Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [13B-MSP] .)
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE [13B-MSP] .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [13B-MSP] .)
9		No	DTC troubleshooting completed.