P2672 – Actuator Supply Voltage “C” Circuit Range/Performance

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Range/Performance | Location: Designator C

Definition source: SAE J2012/J2012DA (industry standard)

P2672 indicates the powertrain control module has detected a range/performance problem in the Actuator Supply Voltage “C” circuit. In plain terms, the module expected the “C” supply feed to behave within an acceptable operating window and respond appropriately under commanded conditions, but what it measured or inferred did not match that expectation. This is a plausibility-type fault, not a simple “high” or “low” electrical input code, and it does not by itself prove an actuator or module has failed. Circuit naming, what devices share that supply, and the exact monitoring logic vary by vehicle, so confirm the circuit identity, pinouts, and test criteria using the correct service information before beginning diagnosis.

What Does P2672 Mean?

P2672 – Actuator Supply Voltage “C” Circuit Range/Performance means the control module has determined that the actuator supply voltage circuit labeled “C” is not performing as expected. Per SAE J2012 DTC structure, this is a standardized powertrain diagnostic entry describing a monitored circuit whose behavior falls outside an acceptable range or fails plausibility checks during self-tests or normal operation. Depending on design, “Supply Voltage C” may be a dedicated feed to a single actuator or a shared supply for multiple actuators. The fault is set when the module’s observed supply behavior (such as stability, response to load, or correlation to commanded operation) does not agree with the expected model for that circuit.

Quick Reference

• Subsystem: Actuator Supply Voltage “C” power feed and its distribution to one or more actuators (varies by vehicle).
• Common triggers: Excessive voltage drop under load, unstable supply, poor correlation between commanded actuator activity and measured supply behavior, or supply not recovering properly after load changes.
• Likely root-cause buckets: Wiring/connector issues, power/ground path resistance, actuator overcurrent or internal fault affecting the shared feed, fuse/relay or power distribution faults, control module driver/monitoring faults.
• Severity: Often moderate; may cause reduced performance or protective strategies depending on which actuators are fed by Supply “C”.
• First checks: Scan for related DTCs, inspect fuses/relays and connectors for heat or corrosion, verify grounds, and check for load-related voltage drop on the supply circuit.
• Common mistakes: Replacing an actuator immediately, treating it as a “circuit high/low” code, or skipping voltage-drop testing and load testing of the supply path.

Theory of Operation

Many vehicles distribute a regulated or switched supply feed to actuators through one or more labeled supply circuits (such as “A,” “B,” or “C”). The control module may provide the feed directly, switch it through an internal driver, or control it through an external relay or power distribution device. It also monitors the supply circuit using internal sensing, a feedback line, or inferred behavior (such as current draw effects or actuator response). Under normal operation, the supply remains stable, and any expected change in load or commanded actuator operation results in predictable, repeatable electrical behavior.

A range/performance fault is set when the circuit’s behavior is implausible compared to what the module expects for given operating conditions. Typical triggers include excessive resistance causing abnormal drop under load, intermittent connection causing instability, or an actuator fault that distorts the shared supply characteristics. The monitor may evaluate performance during commanded actuator events, key cycles, or self-tests; exact criteria vary by vehicle and must be verified in service information.

Symptoms

• Warning light: Check Engine Light or malfunction indicator illuminated.
• Reduced power: Limited performance or protective torque management if affected actuators are critical.
• Intermittent operation: Actuator-driven functions may work sporadically, especially over bumps or vibration.
• Rough running: Uneven engine operation if the supply “C” circuit supports engine-related actuators.
• No-start/extended crank: Possible if the impacted actuators are required for starting (varies by vehicle).
• Additional DTCs: Other actuator or supply-related codes that appear alongside P2672.

Common Causes

• Wiring harness damage in the actuator supply voltage “C” feed circuit (chafing, pinched sections, insulation rubbed through)
• Connector issues in the “C” circuit path (loose fit, backed-out terminals, corrosion, moisture intrusion, poor pin contact)
• High resistance in power or ground paths that support the actuator supply network (including shared grounds or splices)
• Intermittent opens or poor continuity at in-line joints, splices, or fuse/relay junction points feeding the actuator supply circuit
• Actuator load problem affecting supply behavior (internal short, partial short, or abnormal current draw that skews the supply circuit’s observed performance)
• Power distribution fault affecting the monitored actuator supply (weak feed, relay contact wear, fuse connection heat damage, poor bus connection)
• Control module output/driver or internal sensing issue for the monitored supply circuit (varies by vehicle architecture)
• Software/calibration or module logic issue causing the monitor to flag a range/performance condition under certain operating states (verify with service information)

Diagnosis Steps

Tools typically needed include a scan tool with live data and recording capability, a digital multimeter, and access to vehicle-specific wiring diagrams and connector views. A test light may help for quick load checks where approved, and basic hand tools for connector inspection. If available, a current clamp and breakout leads can help evaluate actuator loading without damaging terminals.

1. Confirm the DTC and capture freeze-frame data: Verify P2672 is present and note operating conditions when it set (engine state, temperature, commanded actuator states, and any related DTCs). Do not clear anything yet.
2. Check for related powertrain or voltage-related codes: If other actuator supply, reference, battery voltage, or module reset codes are present, address system-level power/ground concerns first since they can drive a range/performance outcome.
3. Identify what “Actuator Supply Voltage ‘C’” refers to on this vehicle: Using service information, locate the specific circuit name, the actuators/modules it feeds, and the control module pin(s) that monitor it. This step prevents testing the wrong supply rail.
4. Perform a visual inspection of the full “C” circuit path: Inspect harness routing from the source (fuse/relay/power distribution) to the actuator(s) and to any module sense wires. Look for rub-through, recent repairs, heat damage, improper tie-downs, and signs of moisture at connectors.
5. Connector and terminal integrity checks: With power off as required, unplug connectors in the “C” circuit path and inspect for corrosion, spread terminals, backed-out pins, damaged seals, or poor retention. Lightly tug test individual wires and verify terminal tension per service procedures.
6. Load-aware supply check (not just static voltage): With the circuit powered and the actuator commanded on/off (or during the enable conditions specified), monitor the actuator supply “C” parameter on the scan tool and compare it to the expected behavior in service information. A range/performance fault often appears only under load or during transitions.
7. Voltage-drop testing on power and ground paths: While the actuator is commanded to operate, measure voltage drop across the power feed side (from power source to actuator supply pin) and across the ground return(s) (from actuator/module ground pin to battery ground). Excessive drop indicates resistance that can cause the monitored supply to fall out of the expected performance window.
8. Wiggle test with live-data logging: With live data recording, gently move the harness, connectors, and known flex points while the actuator is commanded and the monitor is active. Look for momentary supply deviations, actuator dropouts, or changes in commanded vs observed behavior that point to an intermittent connection.
9. Check continuity and isolation where appropriate: With the circuit de-energized and components disconnected as required, verify continuity end-to-end on the “C” feed and sense circuits, and check for unintended continuity to other circuits. This helps find partial opens, shorts between circuits, or splice faults that can distort supply behavior.
10. Evaluate the actuator as a load: If wiring and connections test good, evaluate the actuator(s) on the “C” supply for abnormal load behavior using service-approved tests (functional test, resistance checks only if specified, and/or current measurement). An actuator drawing abnormal current can pull the supply out of its expected range without a simple “high” or “low” hard fault.
11. Assess module output/sensing and finalize: If the vehicle architecture uses a controlled/regulated supply or the module senses the circuit, verify the module’s power/grounds first, then follow service information to test the driver/sense circuit. After repairs, clear codes and run the specified drive cycle or actuator tests to confirm P2672 does not return.

Professional tip: Because P2672 is a range/performance fault, prioritize tests that replicate the conditions when the circuit is active and loaded. A circuit that looks fine with no load can still fail when an actuator is commanded or when vibration/heat changes resistance. Record live data during a repeatable command or road test so you can correlate the supply “C” behavior with the exact moment the monitor fails.

Possible Fixes & Repair Costs

Repair cost for P2672 varies widely because “Actuator Supply Voltage ‘C’ Circuit Range/Performance” can be caused by anything from a simple connection issue to a circuit integrity problem or a control-module output concern. Accurate testing determines whether labor, wiring repair, or component replacement is needed.

• Clean, reseat, and secure connectors in the actuator supply voltage “C” circuit; address loose terminals, poor pin fit, corrosion, or damaged seals found during inspection.
• Repair or replace damaged wiring (chafed insulation, rubbed-through sections, stretched conductors) in the supply feed, return, or related harness routing that affects circuit performance.
• Perform verified power and ground repairs that affect the actuator supply voltage “C” circuit, including correcting high-resistance splices, weak grounds, or shared power distribution faults.
• Repair shorts or unintended coupling that distort the supply behavior under load, including harness contact points and connector back-outs that create intermittent range/performance issues.
• Replace the affected actuator only after confirming the supply circuit is correct and the actuator’s current draw or internal behavior is causing the circuit to perform out of range.
• If service information supports it, update or reprogram the control module and retest; replace a module only after confirming it cannot correctly regulate/monitor the actuator supply voltage “C” circuit.

Can I Still Drive With P2672?

You may be able to drive short distances if the vehicle feels normal, but P2672 indicates the actuator supply voltage “C” circuit is not performing as expected, which can lead to unpredictable actuator operation. If you experience reduced power, stalling, no-start, warning indicators related to vehicle stability or powertrain control, or any safety-related changes, do not continue driving—have the vehicle diagnosed and repaired first.

What Happens If You Ignore P2672?

Ignoring P2672 can allow a marginal supply circuit to worsen, potentially causing intermittent faults to become persistent, more warning lights, drivability issues, and possible failsafe operation. Continued operation with an unresolved range/performance condition can also complicate diagnosis later by adding secondary codes and masking the original root cause.

Related Actuator Supply Codes

Compare nearby actuator supply trouble codes with similar definitions, fault patterns, and diagnostic paths.

• P2684 – Actuator Supply Voltage "F" Circuit Range/Performance
• P2680 – Actuator Supply Voltage "E" Circuit Range/Performance
• P2676 – Actuator Supply Voltage "D" Circuit Range/Performance
• P2692 – Actuator Supply Voltage "H" Circuit Range/Performance
• P2688 – Actuator Supply Voltage "G" Circuit Range/Performance
• P2686 – Actuator Supply Voltage "G" Circuit Low

Key Takeaways

• P2672 is a range/performance fault for the actuator supply voltage “C” circuit, not a guaranteed component failure.
• Most effective repairs start with verifying circuit integrity under load, not replacing parts first.
• Connector condition, harness routing damage, and high-resistance power/ground paths are common root-cause buckets.
• Intermittent issues are common; wiggle testing and live-data logging help catch the fault in action.
• Confirm the verified cause before replacing an actuator or control module.

Vehicles Commonly Affected by P2672

• Vehicles using a dedicated actuator supply voltage circuit labeled by channel (such as “A/B/C”) for multiple loads
• Platforms with electronically controlled powertrain actuators that share a regulated supply feed
• Vehicles with dense engine-bay harness routing near heat sources, sharp edges, or moving components
• Applications with multiple inline connectors or junction points between the control module and actuators
• Vehicles operating in corrosive environments where connector fretting or terminal oxidation is more likely
• High-mileage vehicles where harness strain, vibration, and prior repairs increase resistance or intermittency
• Vehicles with underbody or splash-area harness segments feeding powertrain actuators
• Applications that enter reduced-power strategies when actuator supply behavior is out of expected range

FAQ

Does P2672 mean the actuator is bad?

No. P2672 indicates the actuator supply voltage “C” circuit is outside expected range/performance, which can be caused by wiring, connectors, power/ground distribution, or the actuator drawing abnormal load. Testing is required to confirm the root cause.

What is “Actuator Supply Voltage ‘C’”?

It is a designated supply circuit (channel “C”) used by the control system to power one or more actuators, depending on vehicle design. The label is a circuit identifier; the specific actuator(s) and routing vary by vehicle and should be verified in service information.

Why can P2672 be intermittent?

Range/performance faults often occur only under certain conditions, such as vibration, heat, moisture intrusion, or when an actuator is commanded on and current draw changes. Loose terminals, fretting corrosion, or chafed wiring can cause the supply behavior to drift out of expected performance intermittently.

Will clearing the code fix P2672?

Clearing the code only resets the stored fault; it does not correct the underlying range/performance issue. If the problem remains, the monitor will typically fail again once the system runs its checks under the right operating conditions.

What tests best confirm the problem behind P2672?

The most useful confirmation tests are circuit checks performed under load, including voltage-drop testing on power and ground paths, inspection for connector/terminal issues, and logging relevant live data while commanding the actuator. Always compare results to the vehicle’s service specifications.

For accurate results, identify which actuators are powered by the “C” supply on your vehicle, then test the complete path from the control output through connectors and harness segments to the load while it is operating.