Fix P0223: Mechanic’s solutions that WORKED

The P0223: Throttle/Pedal Position Sensor/Switch B Circuit High Input indicates an issue with the Throttle/Pedal Position Sensor B, where the input signal to the ECM is unexpectedly high. This sensor plays a critical role in regulating the engine’s air intake and throttle control. A high input signal could mean the sensor is sending incorrect information about the throttle’s position, leading to erratic engine behavior.

P0223 quick overview

Meaning	P0223: Throttle/Pedal Position Sensor/Switch B Circuit High Input
Is it serious?	This code is serious as it can lead to erratic throttle response, affecting the vehicle’s driveability and safety.
Possible causes	– Faulty throttle position sensor – Wiring issues or shorts in the throttle position circuit – Problems with the accelerator pedal position sensor – ECM (Engine Control Module) malfunctions
How to diagnose?	Inspect Throttle Body: Examine the throttle body for any physical damage or obstructions. Check Wiring and Connectors: Look for damaged, loose, or corroded wiring and connectors between the throttle body and ECM. Test Sensor Voltages: Measure voltages at the throttle position and accelerator pedal position sensors. Evaluate ECM: Consider the possibility of ECM faults or the need for software updates. Monitor Throttle Response: Observe the throttle response using diagnostic tools for any irregularities.

How to fix P0223 – learn from mechanics

I looked into P0223 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Honda

Vehicle Information:
2008 Honda Civic Si 2.0L

Issue + Repair History:

• MIL lamp on with multiple codes indicating wheel speed malfunction, modulator control unit low voltage, ECM/PCM related failure, CAN bus system failure.
• P0123 and P0223 codes in the PCM.
• Vehicle had clutch replaced recently; no prior issues reported.
• Suspected wiring harness damage, but visual inspection showed no issues.
• Fuses checked and found okay.
• Codes can be erased but return immediately.

Other OBD2 Codes + Test Results:

• 16-17 RR wheel speed malfunction
• 18-17 Left rear malfunction
• 61-1 Modulator control unit low voltage
• 61-1 ECM/PCM related failure
• 86-1 CAN bus system failure
• P0123 – TPS
• P0223 – TPS
• Visual wiring inspection: okay

Suggestions to Fix Issue:

• Suspect open circuit in wire harness.
• Check for continuity between ECM/PCM connector terminal and throttle body connector terminal.
• If no continuity, repair wiring.
• If there is continuity, consider updating or replacing PCM.

Final Fix:

• Wiring issue confirmed; sensor ground was open at PCM.
• Repaired open circuit in wiring, resolving the problems.

Case #2: Kia

Vehicle Information:
2009 Kia Borrego LX 3.8L

Issue + Repair History:

• Vehicle exhibited no throttle response.
• Diagnostic codes P2106, P1295, P0123, and P0223 were present.
• AP sensor tested within specs; discrepancies found in TP sensor readings.
• Replaced throttle body and performed relearn, but the issue persisted with all codes returning.
• Both TPS 1 and TPS 2 voltages were constantly at 5.0 volts after throttle body replacement.

Other OBD2 Codes + Test Results:

• P2106: ETC Limited Power
• P1295: ETC Power Management
• P0123: TP High
• P0223: TB Sensor B High

Suggestions to Fix Issue:

• Check for 5 volts at terminal #1 at the throttle body connector (grey wire).
• Consider the possibility of a wire harness issue near the throttle body.
• TPS sensors should total 5 volts but be opposite of each other.

Final Fix:

• Found a broken ground to ECM caused by rub through on the center factory cable clamp.
• Repairing the ground wire resolved the issue.

Case #3: BMW

Vehicle Information:
2000 BMW X5 4.4i 4.4L

Issue + Repair History:

• Vehicle towed into the shop, starts then runs for a few seconds before dying.
• Initially had multiple codes including P1341, P1355, P1357, P1353, P0302, P0301, P1351, P0116, P0120, P0123, P0223.
• After clearing codes, P0120, P0123, and P0223 returned immediately.
• Intake Air Temperature (IAT) reading consistently at -40°F.
• Mass Air Flow sensor disconnected but issue persisted.

Other OBD2 Codes + Test Results:

• P0120: Throttle Position Sensor/Switch A Circuit Malfunction
• P0123: Throttle Position Sensor/Switch A Circuit High Input
• P0223: Throttle/Pedal Position Sensor/Switch B Circuit High Input

Suggestions to Fix Issue:

• Check the Mass Air Flow sensor connection and functionality.
• Investigate possible flooding in cylinders.
• Perform a wiring integrity test on the air temperature sensor.
• Check for coolant contamination in engine wiring, especially on throttle body.
• Inspect the Electronic Throttle Body and accelerator pedal sensor.
• Consider throttle body relearn procedures; some may require a scan tool.

Final Fix:

• A defective Digital Motor Electronics (DME) module was identified.
• Replaced the Throttle Body Injection (TBI) unit and attempted to clear codes without success.
• Disconnected the battery and DME, then found no codes upon rechecking.
• A borrowed DME from a similar vehicle indicated a normal intake air temperature.
• Planning to send the vehicle to the BMW dealership for further action.

Case #4: Mazda

Vehicle Information:
2012 Mazda 5 Sport 2.5L

Issue + Repair History:

• Vehicle showing P0123 and P0223 codes (TPS circuit high input).
• RPM rises up to 2,000, causing a clunk when shifting.
• Issue occurs when vehicle is fully warmed up or in hot weather.
• Throttle body replaced twice, first with a Cardone remanufactured part, then with a Mazda OE part.
• Replaced and programmed PCM.
• Checked wires between throttle body and PCM, and PCM grounds, with no faults found.

Other OBD2 Codes + Test Results:

• P0123: TP sensor No.1 circuit high input
• P0223: TP sensor No.1 circuit high input

Suggestions to Fix Issue:

• Check if the wire harness between PCM and sensors is pinched or damaged and crossed over to a 12-volt circuit.
• Conduct a wiggle test and monitor live data for any irregularities in waveforms.
• Consider the possibility of a fault in the Throttle Pedal Position (TPP) rather than the Throttle Position Sensor (TPS).
• Short the signal to the ground and check if it goes to low volts in the scanner to determine if there is a broken wire.

Final Fix:

• The problem was with the PCM. Replaced the second used PCM with a Mazda PCM and programmed it, resolving the issue.
• Kept the vehicle for a week for observation before releasing it to the customer.
• The vehicle is now shifting perfectly with no high voltage reading at TPS.

Case #5: Nissan

Vehicle Information:
2010 Nissan Rogue S 2.5L

Issue + Repair History:

• Vehicle stalled while driving, check engine light came on, and it would not restart.
• Battery was leaking, and the positive fuses were damaged.
• After replacing the battery and fuse clamp, the vehicle started but ran for only 30 seconds and died.
• Initial codes: P0643, P0223, P0123.
• Throttle body replaced, but problem persisted.
• Replaced PCM, but the issue continued.

Other OBD2 Codes + Test Results:

• P0643: Sensor Power/Circuit
• P0223: TP Sensor 1 Circuit High Volt
• P0123: TPS or APP Sensor High Voltage/Open
• Fuel pressure: 52 psi

Suggestions to Fix Issue:

• Check for possible damage or short in the wire harness between PCM and sensors.
• Disconnect the Mass Air Flow sensor and check if the vehicle runs.
• Investigate NATS (anti-theft) system and key reinitialization.
• Consider a fault in the IPDM (Intelligent Power Distribution Module).
• Examine PCM grounds and 5-volt reference signals.
• Perform tests with a scope to check injector pulse and fuel quality.

Final Fix:

• Replacing the PCM with a new unit and programming the security system with Autel resolved the issue.
• Vehicle kept for observation before releasing to the customer to ensure the problem was fixed.

Advice	Diagnostic Step Description
Check Throttle Body	Inspect the throttle body for faults, cleanliness, and proper operation.
Inspect Wiring and Connectors	Examine wiring and connectors between throttle body, sensors, and PCM for damage, corrosion, or loose connections.
Verify Sensor Voltages	Measure the voltage at TPS (Throttle Position Sensor) and related sensors to ensure they are within specified range.
Test 5-Volt Reference Circuits	Check the 5-volt reference circuits from the PCM to ensure they are not shorted and providing correct voltage.
Examine PCM and Programming	Inspect the PCM for faults and ensure it is properly programmed.
Consider Sensor Replacements	Replace sensors like TPS or APP (Accelerator Pedal Position) if diagnostics indicate a fault.
Check for Software Updates	Ensure the vehicle’s software is up-to-date, as some issues might be resolved with firmware updates.
Perform Ground and Continuity Tests	Conduct ground and continuity checks on relevant circuits to rule out electrical issues.