P2058 Reductant Injection Valve Circuit High Bank 2 Unit 2

P2058 Reductant Injection Valve Circuit High Bank 2 Unit 2 is a generic OBD-II diagnostic trouble code indicating that the vehicle's Engine Control Module (ECM), Powertrain Control Module (PCM), or aftertreatment control module has detected an abnormally high electrical signal in the circuit controlling a reductant injection valve associated with Bank 2, Unit 2.

In simple terms, the vehicle's computer has detected that the electrical voltage or control signal for the relevant reductant injection valve is higher than the expected operating range.

The reductant injection system is used on certain diesel vehicles to control exhaust emissions. The system injects a reductant into the exhaust stream so the emissions-control system can reduce nitrogen oxide (NOx) emissions.

On many modern diesel vehicles, the reductant is Diesel Exhaust Fluid (DEF), commonly known as AdBlue in Europe.

Important: The exact meaning of "Bank 2" and "Unit 2" can vary significantly depending on the vehicle manufacturer's exhaust-aftertreatment system. Some vehicles use multiple dosing valves, multiple exhaust banks, or separate aftertreatment units. Therefore, the exact component location should always be confirmed using the manufacturer's service information.

Possible causes of P2058 include:

• Open circuit

• Short to battery voltage

• Broken control wire

• Disconnected connector

• Corroded connector

• Faulty reductant injection valve

• Open or internally damaged valve coil

• Faulty power supply

• Damaged wiring

• Incorrect wiring repair

• Faulty relay

• Control-module driver failure

• Incorrect replacement component

• Software or calibration problem

P2058 does not automatically mean that the reductant injection valve is defective. The wiring, connector, power supply, ground, and control circuit should be tested before replacing the valve.

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What Does P2058 Mean?

The code description contains several important parts.

Reductant

Reductant is a fluid used by certain diesel emissions-control systems to reduce pollutants in the exhaust.

On many vehicles, this fluid is DEF/AdBlue.

DEF is injected into the exhaust system and works with the Selective Catalytic Reduction (SCR) system to reduce NOx emissions.

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Injection Valve

The reductant injection valve controls the flow of reductant into the exhaust system.

The control module commands the valve to open and close according to factors such as:

• Engine load

• Engine speed

• Exhaust temperature

• NOx sensor readings

• SCR catalyst conditions

• Reductant system pressure

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Bank 2

Bank 2 generally refers to the exhaust or engine side associated with the second bank.

On many V-type engines:

• Bank 1 contains cylinder number one.

• Bank 2 is the opposite side.

However, in complex aftertreatment systems, the manufacturer's definition of Bank 2 should be confirmed.

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Unit 2

Unit 2 identifies the second relevant component or aftertreatment position in the manufacturer's system.

Depending on the vehicle, this can refer to:

• The second reductant injector

• A second dosing valve

• A second exhaust aftertreatment unit

• A second SCR dosing location

Do not assume the physical location without a manufacturer-specific wiring diagram or component-location diagram.

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Circuit High

"Circuit High" means the control module has detected a voltage or electrical signal above the expected range.

This does not necessarily mean that the valve is mechanically stuck open.

P2058 primarily indicates an electrical circuit problem.

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How Does the Reductant Injection System Work?

A typical SCR system operates as follows:

1. DEF/AdBlue is stored in a dedicated tank.

2. The control system monitors reductant level and temperature.

3. A supply pump moves reductant toward the dosing system.

4. The control module calculates the required dosing quantity.

5. The reductant injection valve receives an electrical command.

6. The valve opens at the appropriate time.

7. DEF is injected into the exhaust system.

8. Exhaust heat converts the DEF into ammonia-containing compounds.

9. The SCR catalyst uses these compounds to reduce NOx.

10. Downstream NOx sensors monitor system performance.

11. The control module adjusts dosing as necessary.

If the electrical signal in the injection-valve circuit remains abnormally high, P2058 may be stored.

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Why Is Reductant Injection Important?

Correct reductant dosing helps:

• Reduce NOx emissions

• Maintain SCR catalyst efficiency

• Meet emissions requirements

• Protect aftertreatment components

Incorrect dosing can result in:

• Increased emissions

• SCR efficiency faults

• Reductant consumption problems

• Engine power restrictions

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Symptoms of P2058

Check Engine Light

The Check Engine Light is a common symptom.

The control module may illuminate the warning lamp when the high circuit signal is detected.

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DEF/AdBlue Warning

The vehicle may display an emissions-system warning.

Possible messages include:

• Check DEF

• Check AdBlue

• AdBlue system fault

• DEF system malfunction

• Exhaust fluid system fault

• Emissions system fault

The exact warning depends on the manufacturer.

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Reduced Engine Power

Some vehicles may reduce engine torque when the emissions system cannot operate correctly.

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Vehicle Speed Restriction

Certain SCR-equipped vehicles may eventually impose a speed limitation if the fault remains unresolved.

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Increased NOx Emissions

A defective reductant injection circuit can prevent the SCR system from operating correctly.

This may increase NOx emissions.

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Incorrect Reductant Dosing

The dosing valve may not receive the correct electrical command.

This can cause:

• Reduced dosing

• Incorrect dosing

• Interrupted dosing

• SCR efficiency problems

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Additional Aftertreatment Fault Codes

P2058 may appear together with codes related to:

• DEF/AdBlue

• Reductant pressure

• SCR efficiency

• NOx sensors

• Dosing injectors

• Aftertreatment modules

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No Noticeable Driving Symptoms

Some vehicles may initially drive normally.

The fault may primarily affect emissions-system operation.

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Common Causes of P2058

Short to Battery Voltage

A control wire contacting a positive voltage source can cause the circuit voltage to remain high.

This is one of the important causes of a circuit-high code.

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Open Control Circuit

On some system designs, a broken or disconnected control wire can result in a high voltage being detected because the circuit is pulled up internally.

Therefore, a "circuit high" code does not always mean the circuit is directly shorted to battery voltage.

The manufacturer's circuit design must be checked.

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Broken Wiring

A broken control wire can interrupt the expected electrical path.

Possible causes include:

• Vibration

• Exhaust heat

• Road debris

• Corrosion

• Previous repairs

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Faulty Reductant Injection Valve

The injection valve may have an internal electrical failure.

Possible faults include:

• Open valve coil

• Internal electrical damage

• Connector failure

• Internal wiring failure

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Corroded Connector

Moisture and contamination can damage the electrical connection.

Check for:

• Green corrosion

• White deposits

• Water intrusion

• Bent terminals

• Loose pins

• Damaged seals

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Disconnected Connector

A connector that is not fully seated can interrupt the electrical circuit.

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Damaged Wiring

The wiring harness can be damaged by:

• High exhaust temperatures

• Vibration

• Abrasion

• Road debris

• Water

• Salt

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Faulty Power Supply

An abnormal power supply can create a circuit-high condition depending on the system design.

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Faulty Relay

A defective relay may cause an abnormal electrical condition in the dosing circuit.

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Incorrect Wiring Repair

A previous repair may have:

• Connected the control wire to the wrong circuit

• Connected the wire to battery voltage

• Reversed terminals

• Left an important wire disconnected

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Incorrect Replacement Component

An incorrect injection valve may have different electrical characteristics.

This can cause the control module to detect an abnormal circuit condition.

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Faulty Control Module Driver

The ECM, PCM, or aftertreatment control module may use an electronic driver to control the injection valve.

A failed driver can create an abnormal high signal.

The module should not be replaced until the wiring and valve have been tested.

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Software or Calibration Problem

In rare cases, incorrect module software or calibration can contribute to a recurring circuit fault.

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Contaminated DEF/AdBlue

Contaminated or incorrect DEF can cause mechanical dosing problems.

However, DEF contamination by itself does not normally cause an electrical circuit-high code.

P2058 should first be diagnosed as an electrical problem.

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Vehicles Commonly Affected by P2058

P2058 can occur on diesel vehicles equipped with SCR and the applicable reductant injection valve configuration.

Examples may include:

• Ford F-250 Super Duty

• Ford F-350 Super Duty

• Ford F-450 Super Duty

• Ford Transit Diesel

• Chevrolet Silverado Duramax

• Chevrolet Express Diesel

• GMC Sierra Duramax

• GMC Savana Diesel

• Ram 2500

• Ram 3500

• Mercedes-Benz Sprinter

• Volkswagen Touareg TDI

• Volkswagen Transporter

• Audi Q7 TDI

• BMW X5 Diesel

• Peugeot Boxer Diesel

• Citroën Jumper

• Fiat Ducato Diesel

• Iveco Daily

• Renault Master

• Opel Movano

This list is not exhaustive.

Because Bank 2 Unit 2 is system-specific, P2058 should always be interpreted using the vehicle manufacturer's diagnostic information.

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How Is P2058 Diagnosed?

P2058 should be diagnosed as a circuit-high electrical fault.

The goal is to determine whether the abnormal voltage is caused by:

• Short to battery voltage

• Open circuit

• Faulty valve

• Damaged wiring

• Connector problem

• Incorrect power supply

• Control-module driver problem

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Step 1: Scan for Additional Trouble Codes

Retrieve all stored and pending codes.

Look for related codes involving:

• Reductant injection

• DEF/AdBlue

• Dosing valve

• Reductant pressure

• NOx sensors

• SCR efficiency

• Aftertreatment module

• Electrical power supply

• Communication

Additional codes can provide important diagnostic information.

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Step 2: Check Freeze-Frame Data

Record the conditions when P2058 was stored.

Useful information may include:

• Engine RPM

• Vehicle speed

• Battery voltage

• Exhaust temperature

• Engine load

• Reductant pressure

• Dosing command

• NOx values

• Aftertreatment operating status

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Step 3: Identify Bank 2 Unit 2

Use the manufacturer's component-location information.

Identify the exact:

• Injection valve

• Connector

• Control wire

• Power supply

• Ground

• Controlling module

This is essential because the location of "Unit 2" is manufacturer-specific.

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Step 4: Inspect the Reductant Injection Valve

Check for:

• Physical damage

• Corrosion

• DEF crystallization

• Connector damage

• Bent terminals

• Water intrusion

Crystallization can cause mechanical problems but should not be confused with the electrical cause of P2058.

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Step 5: Inspect Wiring and Connectors

Follow the harness from the valve toward the controlling module.

Look for:

• Melted insulation

• Broken wires

• Chafed wiring

• Short to power

• Corrosion

• Loose connectors

• Incorrect previous repairs

Pay close attention to wiring routed near hot exhaust components.

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Step 6: Check Battery and Charging Voltage

Verify that the vehicle's electrical system operates correctly.

Check:

• Battery voltage

• Charging voltage

• Battery terminals

• Main power connections

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Step 7: Check the Power Supply

Verify that the injection valve receives the correct power according to manufacturer specifications.

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Step 8: Check the Ground Circuit

Verify the valve's ground circuit where applicable.

A poor ground can create abnormal circuit behavior.

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Step 9: Check for a Short to Battery Voltage

With the circuit safely isolated according to manufacturer procedures, test the control wire for an unwanted connection to battery voltage.

A short to power can cause the circuit voltage to remain high.

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Step 10: Check the Control-Wire Continuity

Check continuity between the valve connector and the appropriate control-module terminal.

A broken wire can produce a high signal on some circuit designs.

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Step 11: Test the Injection Valve Resistance

If the manufacturer provides a resistance specification, disconnect the valve and measure the internal coil resistance.

Possible results include:

• Open circuit

• Excessively high resistance

• Excessively low resistance

An open coil can cause an abnormal circuit reading.

Do not use a generic resistance value because specifications vary.

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Step 12: Perform an Active Test

If supported by the scan tool, command the reductant injection valve.

Monitor:

• Valve command

• Circuit voltage

• Current flow

• Reductant pressure

• Dosing response

If the control module commands the valve but the electrical signal remains abnormally high, further circuit testing is required.

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Step 13: Check the Control Signal

Use a suitable meter or oscilloscope to inspect the control signal.

Depending on the system, the valve may use:

• Switched power

• Ground-side switching

• PWM control

• Electronic driver control

Compare the signal with manufacturer specifications.

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Step 14: Check Related Fuses and Relays

Inspect the applicable:

• Fuses

• Relays

• Power-distribution circuits

A faulty power-control component can create abnormal voltage conditions.

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Step 15: Inspect for Intermittent Faults

Manipulate the wiring harness carefully while monitoring the circuit.

Look for changes in:

• Voltage

• Continuity

• Current

• Control signal

This can identify an internal wire break or loose connection.

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Step 16: Check the Control Module

If the valve, wiring, power supply, ground, and connectors test correctly, check the ECM/PCM or aftertreatment module.

The module's output driver may require testing with specialized diagnostic equipment.

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Step 17: Check Manufacturer Technical Information

Check for:

• Technical Service Bulletins

• Known wiring problems

• Connector faults

• Updated dosing valves

• Software updates

• Calibration procedures

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How to Fix P2058

The correct repair depends on the actual cause of the circuit-high condition.

Repair a Short to Power

Locate the section where the control wire contacts a positive-voltage source.

Repair or replace the damaged wiring.

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Repair Damaged Wiring

Replace or repair:

• Melted wires

• Chafed wires

• Broken conductors

• Corroded wiring

• Incorrect previous repairs

Restore the correct harness routing and heat protection.

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Repair or Replace the Connector

Replace damaged terminals or connectors.

Ensure proper terminal tension and connector sealing.

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Replace the Reductant Injection Valve

Replace the valve if it has an internal electrical fault or fails manufacturer specifications.

The replacement component must match the correct Bank 2 Unit 2 application.

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Repair the Power or Ground Circuit

Repair any damaged power or ground connections found during diagnosis.

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Replace a Faulty Relay

Replace the relay if it does not operate according to specification.

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Repair the Control Circuit

Repair the damaged control wire or electrical driver circuit.

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Repair or Replace the Control Module

If the output driver is proven defective, repair or replace the applicable control module according to manufacturer procedures.

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Update Control Module Software

If a software update addresses P2058, reprogram the relevant control module.

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Clean or Replace the Dosing Valve

If DEF crystallization affects the mechanical operation of the valve, clean or replace it according to manufacturer procedures.

Electrical faults should be repaired separately.

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Perform Required Calibration

After replacing a reductant injection valve, the vehicle may require:

• Reductant system initialization

• Dosing calibration

• Injector adaptation

• DEF system reset

• Aftertreatment module programming

• SCR self-test

The required procedure is vehicle-specific.

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Clear the Code and Verify the Repair

After completing the repair:

1. Clear P2058.

2. Run the appropriate aftertreatment self-test.

3. Monitor the valve control signal.

4. Check circuit voltage.

5. Confirm correct valve operation.

6. Monitor reductant pressure and dosing.

7. Test-drive the vehicle.

8. Rescan for stored and pending codes.

The repair should only be considered complete when P2058 does not return.

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What Happens If P2058 Is Ignored?

If P2058 prevents the reductant injection valve from operating correctly, the SCR system may not receive the required amount of reductant.

Possible consequences include:

• Check Engine Light

• DEF/AdBlue warning

• Increased NOx emissions

• Reduced SCR efficiency

• Incorrect reductant dosing

• Reduced engine power

• Vehicle speed restrictions

• Additional aftertreatment fault codes

On some vehicles, continued operation with an unresolved SCR fault can eventually result in operating limitations.

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Can You Drive With P2058?

Short-term driving may be possible if the vehicle operates normally, but the fault should be diagnosed promptly.

If the vehicle displays a DEF/AdBlue warning, reduced-power message, emissions countdown, or speed limitation warning, service should not be delayed.

Continued driving can potentially result in:

• Reduced engine power

• Increased emissions

• SCR system problems

• Vehicle speed limitations

• Additional aftertreatment faults

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Is P2058 a Serious Code?

P2058 is generally considered a moderate-to-high severity emissions-system fault.

The immediate problem is an abnormally high electrical signal in the reductant injection valve circuit for Bank 2 Unit 2.

Although the vehicle may initially continue to drive normally, a failed reductant injection circuit can compromise SCR operation.

Potential consequences include:

• Increased NOx emissions

• Reduced SCR efficiency

• DEF/AdBlue warnings

• Incorrect reductant dosing

• Reduced engine power

• Vehicle speed limitations

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P2058 vs. P2059 and P2060

These codes identify different electrical conditions in reductant-system circuits.

Code	General Meaning
P2058	Reductant Injection Valve Circuit High Bank 2 Unit 2
P2059	Reductant Injection Air Pump Control Circuit Open
P2060	Reductant Injection Air Pump Control Circuit Low

Although these codes are part of the same general emissions-control area, they can identify different components and should not be treated as identical faults.

P2058 specifically concerns a reductant injection valve circuit associated with Bank 2 Unit 2.

P2059 and P2060 concern the reductant injection air pump control circuit.

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How to Prevent P2058

Not every electrical failure can be prevented, but proper maintenance can reduce the risk of related faults.

Recommended practices include:

• Use the correct DEF/AdBlue specification.

• Keep electrical connectors clean and sealed.

• Repair damaged wiring promptly.

• Protect wiring from excessive exhaust heat.

• Avoid unnecessary modifications to the aftertreatment wiring.

• Address DEF/AdBlue warnings promptly.

• Inspect the dosing valve during aftertreatment service.

• Address DEF crystallization when necessary.

• Use the correct replacement components.

• Follow manufacturer procedures after repairs.

• Maintain the battery and charging system.

• Keep the vehicle maintained according to manufacturer recommendations.

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Final Thoughts

P2058 Reductant Injection Valve Circuit High Bank 2 Unit 2 indicates that the vehicle's control system has detected an abnormally high electrical signal in the circuit controlling the relevant reductant injection valve.

The most common causes include:

• Short to battery voltage

• Open circuit

• Broken control wire

• Damaged wiring

• Corroded connector

• Disconnected connector

• Faulty injection valve

• Open valve coil

• Faulty power supply

• Incorrect wiring repair

• Faulty relay

• Control-module driver failure

• Incorrect replacement component

• Software or calibration problems

The most important point is that P2058 does not automatically mean the reductant injection valve needs to be replaced.

Because this is a circuit-high fault, diagnosis should begin with the electrical system. The exact component identified as Bank 2 Unit 2 should first be confirmed using the manufacturer's information. The technician should then inspect the valve, connector, wiring, power supply, ground, and control signal.

The circuit should be checked for a short to battery voltage and for an open circuit because some control-system designs can interpret a disconnected or broken circuit as a high-voltage condition.

If the valve has an internal open or abnormal electrical condition, replacement may be required. If the valve and wiring test correctly, the control module and output driver should be investigated.

Ignoring P2058 can eventually lead to DEF/AdBlue warnings, increased NOx emissions, reduced SCR efficiency, incorrect reductant dosing, reduced engine power, vehicle speed limitations, and additional aftertreatment faults.

The correct repair is to identify the source of the abnormal high signal, repair the wiring or electrical circuit or replace the failed component, perform any required calibration, clear the code, and verify that the reductant system operates correctly without P2058 returning.