P0930 – Gear Shift Lock Solenoid Control Circuit Low

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit Low

Definition source: SAE J2012/J2012DA (industry standard)

P0930 indicates the control module has detected a low input condition in the gear shift lock solenoid control circuit. This circuit is used to manage the shift-lock function that helps prevent unintended movement out of Park unless enabling conditions are met (design varies by vehicle). A “circuit low” fault is an electrical finding, not a confirmed component failure; it typically points to an abnormally low signal or insufficient electrical potential at the monitored point. Because wiring layouts, power feeds, grounds, and module strategies differ across platforms, the exact diagnostic path and expected readings vary by vehicle. Always confirm circuit routing, connector pinouts, and test specifications using the correct service information for the vehicle you are working on.

What Does P0930 Mean?

P0930 – Gear Shift Lock Solenoid Control Circuit Low means the powertrain control system has identified that the gear shift lock solenoid control circuit is reading lower than expected during commanded operation or self-checks. Under SAE J2012 DTC conventions, “circuit low” faults generally indicate an electrical condition such as a short-to-ground, an open power/feed, excessive resistance causing a voltage drop, or a driver/output that cannot raise the circuit to the required state. The code does not, by itself, prove the solenoid is mechanically stuck or that any single component is failed; it only confirms the module saw a low electrical condition in the monitored control circuit.

Quick Reference

• Subsystem: Gear shift lock solenoid control circuit (shift-lock actuator control and its wiring/power/ground path).
• Common triggers: Commanded shift-lock operation with the circuit voltage staying low; short-to-ground; loss of power feed; excessive resistance at connectors/splices.
• Likely root-cause buckets: Wiring/connector damage; poor ground or weak power feed; shift-lock solenoid/actuator electrical fault; control module driver or internal fault (less common).
• Severity: Typically a functional/safety convenience issue (may prevent shifting out of Park or may disable expected lock behavior); severity depends on how the platform manages shift-lock.
• First checks: Scan for related codes; verify brake-lamp operation (if part of enable logic); inspect connectors/harness routing; check fuses/feeds tied to the shift-lock circuit.
• Common mistakes: Replacing the solenoid first without confirming a short-to-ground or power/ground loss; ignoring connector pin fit/corrosion; skipping voltage-drop checks under load.

Theory of Operation

The gear shift lock solenoid is an electrically controlled actuator that helps control when the shifter can move out of Park. Depending on vehicle design, a control module may supply power and switch ground (low-side control), switch power (high-side control), or manage the circuit through an intermediate module. The module typically enables shift-lock operation only when required inputs are satisfied (varies by vehicle), then commands the solenoid on or off and monitors the control circuit response.

For a “circuit low” fault, the module sees the control circuit remain at a low electrical state when it expects the circuit to transition higher during a commanded condition, or it detects an implausibly low feedback/monitoring signal. Common electrical reasons include a short-to-ground on the control wire, an open or weak power feed, high resistance in the wiring/connectors causing excessive drop under load, or a driver that cannot pull the circuit to the intended state.

Symptoms

• No-shift-from-Park: Shifter may not release from Park when expected.
• Intermittent-release: Shift release may work sometimes, especially after moving the harness or cycling the ignition.
• Warning light: Malfunction indicator lamp or drivetrain warning may illuminate depending on platform strategy.
• Stored code: P0930 may set as current or history, sometimes after repeated key cycles.
• Click missing: No audible/physical solenoid actuation sound or feel during a release attempt (varies by vehicle).
• Shift-lock override use: Manual release/override may be required to move the shifter.

Common Causes

• Power feed issue to the shift-lock circuit: Open fuse, faulty relay (if used), or an open in the B+ supply wiring causing the circuit voltage to stay low.
• Short-to-ground on the control circuit: Chafed insulation, pinched harness, or moisture intrusion pulling the control line low.
• High resistance in wiring or connectors: Corroded terminals, loose pin fit, partially backed-out terminals, or damaged conductors causing excessive voltage drop under load.
• Poor ground path for the solenoid: Loose/contaminated ground connection or broken ground conductor preventing normal current flow and biasing readings low.
• Gear shift lock solenoid fault: Internal coil fault or mechanical binding that changes current draw and results in a low circuit condition being detected.
• Brake input/signal issue (enabling circuit): A related enable signal (commonly brake switch input) not reaching the module as expected, depending on vehicle design, leading the control circuit to remain low.
• Module driver or output stage problem: Control module output driver unable to pull the circuit up as commanded (less common; verify power/ground and wiring first).
• Connector/harness damage at high-movement points: Repeated flexing near the shifter assembly, steering column area, or console harness leading to intermittent opens/shorts that present as circuit low.

Diagnosis Steps

Tools typically needed include a scan tool with live-data and bi-directional controls (where supported), a digital multimeter, and basic backprobing supplies. A wiring diagram and connector pinout from service information are essential because the shift-lock circuit architecture varies by vehicle. A test light or fused jumper can help with quick load checks, and contact-cleaning supplies may be useful for terminals.

1. Confirm the DTC and capture data: Scan all modules for codes. Record freeze-frame data and note any related brake input, transmission range, or power supply codes. Clear codes and see if P0930 resets immediately or only after a specific action.
2. Verify the symptom and operating conditions: With the vehicle secured, attempt the normal shift-lock release procedure. Observe whether the shift lever remains locked/unlocked and whether the behavior changes with brake pedal application. If the vehicle uses a manual release, do not rely on it for diagnosis—use it only to move the vehicle if needed.
3. Check basics: battery condition and power distribution: Verify battery terminals are clean/tight and system voltage is stable. Inspect relevant fuses supplying the shift-lock solenoid and the control module circuits. If a fuse is open, do not replace it repeatedly—identify the short or overload first.
4. Use live data to evaluate inputs that enable shift-lock control: In the scan tool, monitor brake pedal switch status (and any shift-lock/park interlock PIDs if available). Confirm the input changes cleanly with pedal application. If the brake input is incorrect, diagnose that circuit first because the module may never command the solenoid, keeping the control circuit low by design.
5. Command the solenoid (if supported): Use bi-directional control to command the gear shift lock solenoid ON/OFF. Observe whether the command changes state in data and whether the solenoid responds. If the scan tool command changes but the circuit remains low, focus on wiring, solenoid, and driver testing.
6. Perform a targeted visual inspection: Inspect the shifter/console area harness, connectors, and any inline connectors between the module and solenoid. Look for spilled fluid contamination, corrosion, damaged locking tabs, pinched wiring, or signs of prior repairs. Correct obvious issues and re-test.
7. Wiggle test for intermittent shorts/opens: With the scan tool on live data (and/or while commanding the solenoid), gently move the harness at known flex points and connectors. Watch for sudden changes in command feedback, brake input status, or the DTC status. If results change during movement, isolate the exact segment causing the fault.
8. Check the solenoid coil and mechanical condition: Key off and connector unplugged as required by service info, measure the solenoid resistance and compare to specifications. Also verify the plunger/mechanism is not binding (varies by design). If resistance is out of spec or the solenoid is physically stuck, replace/repair as appropriate after confirming wiring integrity.
9. Test for short-to-ground on the control circuit: With connectors unplugged as directed, check continuity from the control wire to ground. A low-resistance path indicates a short-to-ground. If present, isolate by disconnecting intermediate connectors and checking each harness segment until the shorted section is found.
10. Verify power and ground under load (voltage-drop testing): Reconnect the circuit and command the solenoid so current flows. Measure voltage drop across the power feed path and across the ground path (from solenoid ground to battery negative). Excessive drop indicates high resistance in wiring, terminals, or grounding points even if static continuity checks seem “good.” Repair the high-resistance point and re-test.
11. Evaluate module output/driver only after the circuit passes: If wiring, connectors, power, ground, and solenoid test good, yet the control circuit remains low when the module commands it, verify the module’s power and grounds with voltage-drop tests. If those are correct and the circuit is proven intact, follow service information for module output testing and replacement/programming steps (varies by vehicle).

Professional tip: Don’t rely solely on key-off continuity checks for a “circuit low” complaint. Many low-input faults are caused by voltage drop under load from corrosion or poor pin fit. Always repeat testing with the solenoid commanded and current flowing, and log live data during the exact moment the fault sets to pinpoint whether the low condition is caused by a supply/ground drop or a control wire being pulled down.

Possible Fixes & Repair Costs

Repair costs for P0930 vary widely because the same “circuit low” fault can be caused by anything from a minor connector issue to wiring repair or component replacement. Final cost depends on confirmed test results, parts accessibility, and labor time.

• Repair wiring faults: Locate and repair short-to-ground, rubbed-through insulation, pinched harness sections, or high-resistance conductors in the gear shift lock solenoid control circuit.
• Restore power/ground integrity: Correct an open feed, poor ground point, or excessive voltage drop by cleaning/tightening connections and repairing damaged terminals.
• Connector service: Reseat connectors; remove corrosion/contamination; repair bent, spread, or backed-out terminals; ensure proper terminal tension and pin fit.
• Replace the gear shift lock solenoid: Replace only after confirming the solenoid’s electrical condition and that command and power/ground to the solenoid are correct.
• Switch/input correction (varies by vehicle): If the control strategy relies on a brake pedal or shift-interlock related input to enable the circuit, repair the proven input/circuit fault that prevents proper operation.
• Module/circuit driver repair (as confirmed): If the control module’s output driver cannot maintain the commanded state and wiring/solenoid test good, follow service information for module testing and replacement procedures.

Can I Still Drive With P0930?

Often the vehicle will still run normally, but P0930 can affect the shift interlock function and may prevent shifting out of Park or cause inconsistent shifter release behavior. If you cannot reliably shift, if any brake-related warning is present, or if the vehicle exhibits unexpected movement risk, do not drive; diagnose and repair the circuit low condition first.

What Happens If You Ignore P0930?

Ignoring P0930 can lead to recurring no-shift-from-Park events, intermittent shifter lock/unlock operation, and repeated warning lights. Continued operation with an unresolved circuit low may also worsen connector heating or wiring damage if high resistance is present, increasing the chance of a complete circuit failure later.

Related Solenoid Gear Codes

Compare nearby solenoid gear trouble codes with similar definitions, fault patterns, and diagnostic paths.

• P0922 – Gear Shift Forward Actuator Circuit Low
• P0929 – Gear Shift Lock Solenoid Control Circuit Range/Performance
• P0931 – Gear Shift Lock Solenoid Control Circuit High
• P0957 – Auto Shift Manual Mode Circuit Low
• P0952 – Auto Shift Manual Control Circuit Low
• P0906 – Gate Select Position Circuit Low

Key Takeaways

• P0930 is an electrical fault: It indicates a “Gear Shift Lock Solenoid Control Circuit Low” condition, not a confirmed mechanical shifter failure.
• Start with wiring and connections: Shorts-to-ground, opens in power feed, poor grounds, and terminal issues are common causes of a low input condition.
• Test before replacing parts: Confirm command, power, ground, and voltage-drop performance before condemning the solenoid or control module.
• Intermittent issues are common: Movement-related harness faults may only appear during a wiggle test or when logs are reviewed.
• Safety matters: If shifting out of Park is unreliable, treat it as a safety concern and repair promptly.

Vehicles Commonly Affected by P0930

• Vehicles with automatic transmissions that use an electronically controlled shift-interlock solenoid
• Vehicles with floor-mounted shifters where the interlock solenoid is integrated into the shifter assembly
• Vehicles with column shifters that use an interlock actuator and dedicated control circuit
• Vehicles with console assemblies prone to spills/contamination reaching connectors (varies by vehicle design)
• High-mileage vehicles with harness wear near the steering column, console, or transmission tunnel
• Vehicles operated in harsh environments where corrosion can affect grounds and connector terminals
• Vehicles with recent interior or brake service where connectors may be disturbed or left partially seated
• Vehicles with frequent stop-and-go operation that cycles the interlock circuit repeatedly

FAQ

Does P0930 mean the gear shift lock solenoid is bad?

No. P0930 only reports that the gear shift lock solenoid control circuit is reading low. That can be caused by wiring damage, poor connections, an open power feed, a weak ground, or a failed solenoid. Testing is required to identify the confirmed root cause.

What is the most common reason for a “circuit low” condition?

The most common electrical reasons are a short-to-ground on the control wire, an open or high-resistance power supply to the solenoid, or a poor ground path that creates excessive voltage drop under load. Connector terminal problems can produce the same symptom.

Can a low battery cause P0930?

Low system voltage can contribute to faults if it causes the solenoid circuit voltage to drop below what the module expects, but it should not be assumed as the cause. Verify battery/charging health, then confirm the solenoid circuit power, ground, and wiring integrity under operating conditions.

Will clearing the code fix the problem?

Clearing the code only erases the stored fault record; it does not correct the underlying circuit low condition. If the fault is still present, the code will typically return when the monitor runs again and sees the control circuit remain low.

What should I check first if the shifter won’t come out of Park?

First confirm basic electrical integrity: inspect related fuses (if used on that circuit), verify the connector is fully seated, and check for obvious harness damage near the shifter and along the harness routing. If those pass, use service information to test the solenoid control circuit for shorts-to-ground and perform voltage-drop tests on the power and ground paths while the circuit is commanded.

For best results, follow the vehicle’s service information to identify the correct connector pins and test points for the gear shift lock solenoid control circuit, then confirm the exact cause with load testing rather than relying on visual inspection alone.