P1720 — SSA Inductive Signature Malfunction

Will P1720 clear itself?

Sometimes P1720 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What are the symptoms of P1720?

Drivers most often notice: Check Engine Light on, possible limp mode depending on the affected component, increased fuel consumption in some cases, the affected system operates intermittently or not at all.

How much does it cost to fix P1720?

Control module repair — $300–$1,000; Repair wiring or connectors — $80–$250; Replace the faulty sensor or actuator — $150–$500. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Is it safe to drive with P1720?

In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

What does OBD2 code P1720 mean?

P1720 — SSA Inductive Signature Malfunction. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: blown fuse feeding the circuit, poor ground connection, faulty sensor or actuator of the affected circuit.

When the check engine light illuminates and a scan tool retrieves code P1720, it signals that the powertrain control module has identified a fault within the SSA inductive signature circuit. P1720 falls into the manufacturer-specific category of OBD2 codes, which means it relates to a particular system's operation rather than a universal emission-related fault. The SSA (Shift Solenoid Actuator or similar actuator, depending on the manufacturer) inductive signature refers to the electrical characteristics the control module expects to see when it tests that circuit.

The engine control module continuously monitors the SSA circuit through a process called an inductive signature test. This test sends a small electrical pulse through the circuit and measures how the system responds. When the module detects a response that falls outside acceptable parameters—either too strong, too weak, or intermittent—it flags this as a problem. P1720 is set when the self-test repeatedly fails across multiple drive cycles, and at that point the control module activates the malfunction indicator light. Unlike a simple short or open circuit problem, this code indicates something about the circuit's electrical signature itself is wrong. This could stem from a failing component, a wiring issue, or even a problem within the control module itself.

The freeze frame data stored alongside P1720 captures the exact operating conditions when the fault occurred—engine speed, load, temperature, and vehicle speed. This information proves invaluable during diagnosis because it shows whether the problem appears at idle, under heavy load, or during a specific temperature range. Rather than guessing, you can replicate those conditions and observe whether the fault reappears.

Common Symptoms of P1720

• The check engine light remains illuminated after the fault is detected
• The vehicle may enter limp mode, restricting power and shift performance depending on which component is affected
• Fuel economy may worsen noticeably in some applications
• The SSA circuit operates inconsistently or ceases to function entirely
• Unusual shifting behavior or failure of specific transmission functions may accompany the code
• In rare cases, no additional symptoms are present beyond the stored code

What Causes P1720?

• Internal failure of the SSA inductive signature component itself
• Wiring damage such as opens, shorts, or chafed insulation within the circuit
• Corroded, loose, or physically damaged electrical connectors
• Inadequate ground connection at the component or module
• Control module driver failure affecting the SSA circuit output
• Software anomaly within the powertrain control module
• Faulty sensor or actuator receiving incorrect signals from the module

How to Diagnose P1720

1. Connect an OBD2 scanner and verify P1720 is stored, then record all freeze frame data—this shows the precise engine conditions present when the module detected the fault.
2. Search for any related diagnostic trouble codes that may have appeared alongside P1720, as secondary codes often point directly to the root cause; also check manufacturer technical service bulletins for known fixes related to this code.
3. Perform a thorough visual inspection of the wiring harness and connectors associated with the SSA circuit, looking for damaged insulation, corrosion buildup, bent pins, or loose connections.
4. If your scan tool supports bidirectional controls, run the module's actuator test for the SSA circuit—a component that fails to respond to direct commands is almost certainly defective.
5. With the connector unplugged, measure reference voltage, ground integrity, and signal continuity at the component harness using a multimeter; compare readings against manufacturer specifications.
6. Conduct a wiggle test on the wiring harness while monitoring live data—the fault will reappear if broken wires lose contact during movement.
7. Clear P1720, perform a complete drive cycle that reproduces the conditions captured in the freeze frame, and verify the code does not return.

Repair Options and Costs for P1720

The appropriate repair depends entirely on what the diagnostic process reveals. Wiring and connector repairs typically cost between $80 and $250 for parts and labor at an independent shop. If the SSA sensor or actuator itself has failed, replacement runs approximately $150 to $500 depending on the specific component and vehicle application. When the powertrain control module is at fault, repair or replacement ranges from $300 to $1,000.

Total repair costs for P1720 generally fall between $80 and $1,000, with the final figure determined by which component actually failed. An accurate diagnosis before purchasing parts is essential—the most expensive scenario is rarely the first one to investigate, and many P1720 issues trace back to simple wiring problems that cost far less to repair than a new control module.

Can You Drive with P1720?

In most driving situations, the vehicle remains operational when P1720 is stored, though you may notice reduced performance, altered shift characteristics, or a disabled auxiliary system depending on which SSA circuit is affected. If the code is accompanied by stalling, failure to start, or warnings related to braking or steering systems, treat the situation as urgent and seek repair immediately. Otherwise, schedule diagnostic testing at your earliest convenience to prevent potential escalation.