P1D23 – Power circuit (pre-charge fail) (Mitsubishi)

Mitsubishi-specific code — factory diagnostic data

Last updated: March 29, 2026

Definition source: Mitsubishi factory description · Autel MaxiSys Ultra & EV. Diagnostic guidance is based on factory-defined fault logic for this code.

P1D23 means your 2016 Mitsubishi Outlander detected a pre-charge failure in the power circuit. In plain terms, the vehicle may refuse to “Ready,” may limit power, or may shut down to protect the high-voltage system. This is a Mitsubishi manufacturer-specific code, so the exact checks and the module that sets it can vary by platform. According to Mitsubishi factory diagnostic data, this code indicates a “Power circuit (pre-charge fail).” The code does not prove a bad part. It tells you the pre-charge process did not complete as expected, so you must confirm the electrical path and control logic before replacing components.

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P1D23 Quick Answer

P1D23 on Mitsubishi points to a failed pre-charge event in the power circuit. Diagnose the pre-charge command, current path, and feedback signals before replacing the inverter, contactors, or the 12V battery.

What Does P1D23 Mean?

Official definition: “Power circuit (pre-charge fail)” (Mitsubishi). What the module detected: the control system commanded pre-charge, but it did not see the expected rise and stabilization of the HV DC bus during the allowed time. What that means in practice: the vehicle protects the HV components by blocking contactor closure, dropping out of READY, or limiting torque.

What the module is actually checking: it monitors pre-charge relay/contactor control, HV bus voltage feedback, and plausibility between measured voltages. Some Mitsubishi platforms also cross-check insulation monitoring status and contactor weld detection logic. Why that matters for diagnosis: a weak 12V supply, a high-resistance connection, or a biased voltage sensor can all mimic a “failed pre-charge” even when the main components remain good. Treat P1D23 as a suspected circuit and process fault, not a confirmed inverter failure.

Theory of Operation

During a normal start to READY, Mitsubishi’s HV control system charges the inverter capacitor bank in a controlled way. It does that through a pre-charge path that limits inrush current. The system then confirms the HV DC bus voltage rises smoothly to a target range. After that check passes, it closes the main contactors to support full current flow.

P1D23 sets when the pre-charge sequence breaks. The HV bus may rise too slowly, rise erratically, or not rise at all. A low 12V feed can prevent relays from pulling in. A high-resistance cable or a damaged pre-charge resistor can also stall the voltage ramp. Incorrect feedback from a voltage sensing circuit can trigger the same code because the module will not “trust” the HV bus status.

Symptoms

You will usually notice a no-READY condition or a reduced-power fail-safe when this code sets.

• Warning message EV system warning, hybrid system warning, or a “READY” light that fails to turn on
• No start/No READY vehicle powers up but will not enter READY mode
• Reduced power limited acceleration or torque reduction as a protection strategy
• Intermittent starts starts normally sometimes, then refuses READY on the next key cycle
• Clicking sounds repeated relay/contactor clicks during start attempts
• Charging concern charging session aborts or refuses to initiate on some conditions
• Multiple DTCs related HV, inverter, or power supply codes appearing with P1D23

Common Causes

• Weak 12-volt supply during pre-charge: Low system voltage or a voltage sag can keep the pre-charge sequence from completing and trigger a power circuit pre-charge fail.
• Blown fuse or faulty power distribution to the pre-charge path: An open fuse link, fusible link, or junction block fault can remove power from the pre-charge control circuit.
• High resistance in power or ground connections: Corrosion at the battery terminals, ground points, or power studs can limit current and prevent the capacitors from charging in time.
• Open or short in the pre-charge control wiring: A damaged harness can interrupt the command or feedback path and cause the module to detect an incomplete pre-charge event.
• Connector problems at the inverter/drive unit or power electronics: Poor pin fit, water intrusion, or heat damage can create intermittent contact and set P1D23 during key-on or gear engagement.
• Pre-charge relay/contactor control circuit fault: A failed relay coil, driver circuit, or coil feed can stop the relay from closing when the module commands pre-charge.
• Pre-charge resistor path fault: An open resistor element or an open resistor bypass path can prevent controlled charging of the DC link and cause a pre-charge time-out.
• Incorrect feedback signal to the control module: A skewed voltage sense input or reference issue can make the module “think” pre-charge failed even when the circuit works.
• Module logic inhibited by related faults: Mitsubishi will often block pre-charge when other HV, interlock, or power supply DTCs set first.

Diagnosis Steps

Use a professional scan tool that can read Mitsubishi manufacturer-specific powertrain and hybrid/EV data, plus a DVOM and a headlamp-style load tool. You also need wiring diagrams and connector views for the Outlander platform. Plan for voltage-drop testing under load. Use proper high-voltage safety practices and disable HV only per Mitsubishi procedures.

1. Confirm P1D23 and record stored, pending, and history codes. Save freeze frame data, focusing on battery voltage, ignition state, READY/drive enable status, and any pre-charge or inverter status PIDs. Freeze frame shows the conditions when the DTC set. Use a scan tool snapshot later to capture live data during an attempted READY event.
2. Inspect the power distribution path before meter work. Check battery terminals for looseness and inspect main grounds and power studs for corrosion. Then check all related fuses and fusible links that feed the power electronics, control relays, and control module. Do not jump to component replacement yet.
3. Verify 12-volt battery health and charging support. Load test the 12-volt battery and watch for a voltage drop during key-on and during an attempted READY transition. A pre-charge event needs stable supply voltage to drive relays and read feedback correctly.
4. Check module power and ground with voltage-drop testing under load. Back-probe the control module and relevant relay control feeds while commanding the system ON. Measure voltage drop from battery positive to the module power pin, and from the module ground pin to battery negative. Keep ground drop under 0.1 V with the circuit operating. Do not rely on continuity tests alone.
5. Perform a targeted visual inspection of the pre-charge circuit connectors and harness routing. Focus on connectors at the inverter/power electronics, relay/contactor assembly, and any junction blocks in the circuit path. Look for water tracks, terminal push-out, heat discoloration, or harness pinch points. Repair obvious wiring damage before deeper tests.
6. Use the scan tool to review related data and DTC context. Look for other power circuit, HV interlock, relay, or voltage sense codes that set first. Mitsubishi logic often blocks pre-charge when another fault appears. If the scan tool reports a pending code only, treat it as an intermittent or one-trip event until it repeats.
7. Command the pre-charge function with the scan tool if Mitsubishi service functions allow it. Monitor relay/contactor command PIDs and feedback PIDs during the attempt. If the command toggles but feedback does not change, treat it as a control circuit, relay coil, or feedback issue. If the command never occurs, focus on inhibit inputs and module power/ground integrity.
8. Test the pre-charge relay/contactor control circuit electrically. Check for proper coil feed and driver control when the module commands pre-charge. Load the circuit where possible to reveal high resistance. If the driver provides ground control, verify the driver can pull the circuit down under load and does not float due to resistance or a poor connector.
9. Verify the pre-charge resistor and its path per Mitsubishi service information. Confirm the resistor circuit is not open and the wiring supports current flow. Use resistance checks only with the system powered down and made safe. If the circuit uses a bypass contactor, confirm the bypass does not close early and short-circuit the pre-charge stage.
10. If the wiring and controls test good, validate the voltage sense feedback circuit. Inspect the voltage sense connector pins and verify the sense line integrity and reference supply where applicable. A skewed sense input can report an incorrect DC link rise rate and trigger P1D23 even with functional hardware.
11. Confirm the repair with a controlled key-cycle and multiple READY attempts. Clear codes, then repeat the same conditions seen in freeze frame. Recheck for pending and stored codes after a complete drive cycle. If Mitsubishi treats this as a two-trip logic, verify the code does not return on the second consecutive drive cycle.

Professional tip: Treat P1D23 as a “sequence failure,” not a single part failure. The module expects a predictable voltage rise during pre-charge. Use freeze frame to learn whether the fault set during low battery voltage, during a cold start, or right after a key-cycle. Use a scan tool snapshot during a repeated READY attempt to catch an intermittent relay command drop or a momentary voltage sag.

Possible Fixes

• Repair power or ground connection faults: Clean and torque battery terminals, service ground points, and repair corroded power studs after voltage-drop testing confirms high resistance.
• Restore proper fuse and feed integrity: Replace blown fuses or fusible links only after finding the cause of the overcurrent or the open in the feed path.
• Repair harness or connector issues in the pre-charge control/feedback circuits: Fix pin fit, terminal damage, water intrusion, or wiring opens/shorts and then re-run the pre-charge verification.
• Replace a failed pre-charge relay/contactor or resistor only after circuit proof: Replace the component only when command and feed exist, but the component fails functional tests or produces incorrect feedback.
• Correct voltage sense input problems: Repair the sense circuit wiring or connector faults that distort the measured pre-charge voltage rise.
• Address related inhibit DTCs first: Repair the root cause of any primary power circuit or interlock codes that prevent Mitsubishi from allowing pre-charge.

Can I Still Drive With P1D23?

You should treat P1D23 as a “no-start” or “limited-operation” risk on a 2016 Mitsubishi Outlander. This Mitsubishi manufacturer-specific code points to a power circuit pre-charge failure. Pre-charge limits inrush current before high-voltage contactors close. When it fails, the control unit often blocks READY mode, drops propulsion, or commands a fail-safe state. If the vehicle still drives, avoid heavy acceleration and repeated key cycles. Do not continue driving if you see EV system warnings, loss of power, or abnormal electrical odors. Park safely, power down, and diagnose the circuit before more attempts.

How Serious Is This Code?

P1D23 ranges from an inconvenience to a serious drivability concern. When the system only fails on certain key cycles, you may see intermittent no-READY events and warning messages. That situation still needs prompt diagnosis because pre-charge problems tend to worsen. If the Outlander refuses READY mode, the fault becomes immediately disabling. Safety risk increases if the fault causes sudden power reduction while driving. Pre-charge faults also raise electrical stress in the power circuit. That stress can damage contactors, resistors, or connectors. Confirm the cause with scan data and circuit checks before any parts decision.

Common Misdiagnoses

Technicians often replace major components too early with P1D23. The common trap involves condemning the inverter, battery pack, or contactor assembly without verifying the pre-charge command and feedback. Another frequent error involves checking voltage with no load and calling the circuit “good.” Pre-charge faults show up under load, so you need voltage-drop tests and connector inspection. Some skip freeze-frame data and miss the pattern, such as failures only after charging or after a long soak. Others ignore weak 12-volt supply issues. Low auxiliary voltage can prevent proper relay control and create false pre-charge failures.

Most Likely Fix

The most frequently confirmed repair directions involve restoring correct power and control to the pre-charge path, not replacing the biggest module first. Start by fixing high-resistance connections in the power circuit, especially at serviceable connectors and grounds related to the pre-charge and contactor control. Next, verify the pre-charge relay/contactor command and the associated feedback circuit. If tests prove the relay or pre-charge resistor fails electrically, replace only the verified failed component. After repairs, run repeated key cycles and confirm the system enters READY consistently under the same conditions that set the code.

Repair Costs

Repair cost depends on whether the confirmed root cause is a sensor, wiring, connector issue, or control module problem. Verify the fault electrically before replacing parts.