P0A87 Possible Causes

• Faulty 14-volt power module current sensor
• 14-volt power module current sensor harness is open or shorted
• Poor electrical connection in 14-volt power module current sensor circuit

What Does It Mean?

How to Fix Code P0A87

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, ejected, or corroded connector pins.

P0A87 Possible Symptoms

Engine light on (or service engine soon warning light)

P0A87 Meaning

The engine control module (ECM) monitors the 14-volt power module current sensor. The ECM sets the OBDII code when the 14-volt power module current sensor does not meet factory specifications.
OBDII Code P0A87 – 14-volt power module current sensor circuit range/performance

P0A88 Possible Causes

• Faulty 14-volt power module current sensor
• 14-volt power module current sensor harness is open or shorted
• Poor electrical connection in the 14-volt power module current sensor circuit

What Does It Mean?

How to Fix Code P0A88

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0A88 Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P0A88 Meaning

The engine control module (ECM) monitors the 14-volt power module current sensor. The ECM sets the OBDII code when the 14-volt power module current sensor does not meet factory specifications.
OBDII Code P0A88 – 14-volt Power Module Current Sensor Circuit Low

P0A89 Possible Causes

• Faulty 14-volt power module current sensor
• 14-volt power module current sensor harness is open or shorted
• Poor electrical connection in 14-volt power module current sensor circuit

What Does It Mean?

How to Fix Code P0A89

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, ejected, or corroded connector pins.

P0A89 Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P0A89 Meaning

The engine control module (ECM) monitors the 14-volt power module current sensor. The ECM sets the OBDII code when the 14-volt power module current sensor does not meet factory specifications.
OBDII Code P0A89 – 14-volt Power Module Current Sensor Circuit High

P0A8A Possible Causes

• Faulty 14-volt power module current sensor
• 14-volt power module current sensor harness is open or shorted
• Poor electrical connection in 14-volt power module current sensor circuit

What Does It Mean?

How to Fix Code P0A8A

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, ejected, or corroded connector pins.

P0A8A Possible Symptoms

Engine light on (or service engine soon warning light)

P0A8A Meaning

The Engine Control Module (ECM) monitors the 14-volt power module current sensor. The ECM sets the OBDII code when the 14-volt power module current sensor does not meet factory specifications.

P0A8B Possible Causes

• Faulty 14-volt power module
• 14-volt power module harness is open or shorted
• Poor electrical connection in 14-volt power module circuit

What Does It Mean?

How to Fix Code P0A8B

Check the “possible causes” listed above. Visually inspect the related cable harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0A8B Possible Symptoms

Engine light on (or service engine soon warning light)

P0A8B Meaning

The Engine Control Module (ECM) monitors the 14-volt power module. The ECM sets the OBDII code when the 14-volt power module does not meet factory specifications.

P0A8C Possible Causes

• Faulty 14-volt power supply module
• 14-volt power supply module harness is open or shorted
• Poor electrical connection in the 14-volt power supply module circuit

What Does It Mean?

How to Fix Code P0A8C

Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

P0A8C Possible Symptoms

Engine light on (or service engine soon warning light)

P0A8C Meaning

The Engine Control Module (ECM) monitors the 14-volt power supply module. The ECM sets the OBDII code when the 14-volt power supply module does not meet factory specifications.
OBDII Code P0A8C – 14-volt Power Supply Module System Voltage Unstable

🔧 Code P0A8D – Low Voltage in the 14-Volt Power Supply System Module

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❓ What Does Code P0A8D Mean?

The P0A8D code indicates that the Engine Control Module (ECM) has detected insufficient voltage in the vehicle’s 14-volt power supply system.

This module is often used in hybrid or electrified vehicles, where it powers certain components at 14V (different from the traditional 12V system or the high-voltage system).

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⚠️ Possible Symptoms

• Check Engine or Service Engine Soon light illuminated,

• No other noticeable symptoms in some cases,

• In hybrid vehicles: possible partial deactivation of auxiliary electrical systems (air conditioning, power steering, etc.),

• In severe cases: failure to charge the 12V battery.

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🔍 Possible Causes

• Faulty 14V Power Supply Module,

• Open or shorted wiring in the 14V power circuit,

• Loose, corroded, broken, or improperly connected connector,

• Poor ground or poor contact in the circuit.

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🛠️ How to Repair Code P0A8D?

Here are the recommended steps:

1. Visual Inspection

• Locate the 14V power supply module (refer to the manufacturer’s manual),

• Check the connectors: look for bent, corroded, or broken pins,

• Inspect the wires for any damage, cuts, or melting.

2. Check Connections

• Clean all relevant connectors,

• Reconnect them securely after inspection.

3. Electrical Testing with a Multimeter (DVOM)

• Measure the module’s output voltage (it should be close to 14 volts),

• Check the circuit’s ground and continuity,

• Ensure the input power is also correct.

4. Clear Codes and Test

• Clear the code with an OBD-II scanner,

• Start the vehicle and monitor if the code returns.

5. If the Code Returns…

• Replace the 14-volt power supply module if confirmed faulty after testing,

• Also check that the fuse associated with this module is not blown.

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📌 Note

The P0A8D code is often specific to Toyota, Lexus, Honda hybrid vehicles, etc. On these models, the 14V module may be integrated into the inverter or the DC-DC converter. Therefore, it is sometimes necessary to consult a manufacturer’s repair manual to accurately identify the component.

P0A8E Possible Causes

• Faulty 14-volt power supply module
• 14-volt power supply module harness is open or short-circuited
• Poor electrical connection in the 14-volt power supply module circuit

What Does It Mean?

How to Fix Code P0A8E

Check the “possible causes” listed above. Visually inspect the cable harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0A8E Possible Symptoms

Engine light on (or service engine soon warning light)

P0A8E Meaning

The Engine Control Module (ECM) monitors the 14-volt power supply module. The ECM sets the OBDII code when the 14-volt power supply module does not meet factory specifications.

P0A8F Possible Causes

• Faulty 14-volt power module
• 14-volt power module harness is open or shorted
• Poor electrical connection in the 14-volt power module circuit

What Does It Mean?

How to Fix Code P0A8F

Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

P0A8F Possible Symptoms

Illuminated engine light (or service engine soon warning light)

P0A8F Meaning

The Engine Control Module (ECM) monitors the 14-volt power module. The ECM sets the OBDII code when the 14-volt power module does not meet factory specifications.

P0A90 Possible Causes

• Faulty engine assembly
• Faulty HV transaxle assembly (shaft or gear)
• Faulty transmission input damper
• Cable harness or connector
• HV control ECU

What Does It Mean?

How to Fix P0A90 Code

Check the “Possible Causes” listed above. Visually inspect the cable harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

P0A90 Possible Symptoms

Check engine light illuminated (or service engine soon warning light)

P0A90 Meaning

The HV transaxle consists of a planetary reduction gear, MG1 and MG2.
A reduction gear uses the planetary gear to divide engine power according to driving demand during vehicle operation or charging of its internal HV battery.
MG2 provides assistance to engine output while increasing the vehicle’s driving force.

Additionally, MG2 performs regenerative braking by converting energy (which is consumed as heat during normal braking) into electrical energy and recovering it in the HV battery. Through regenerative braking and vehicle deceleration, MG2 generates high voltage electrical power that is used to charge the HV battery.

MG1 provides electrical energy, which is used to charge the HV battery or to drive MG2. It also has a continuous transmission function to control the transaxle by regulating the amount of electrical power generation, which effectively varies MG1 speed. Additionally, MG1 is used as a starter to start the engine.
The transmission input damper absorbs shocks that accompany the transmission of driving force from the engine.