C0357 – Park Switch Circuit High

System: Chassis | Standard: ISO/SAE Controlled | Fault type: Circuit High

Official meaning: Park Switch Circuit High

Definition source: SAE J2012 naming/structure guidance

What Does C0357 Mean?

C0357 – Park Switch Circuit High is an ISO/SAE Controlled diagnostic trouble code in the Chassis system. The official meaning is: Park Switch Circuit High.

This code sets when the monitoring control module detects that the park switch circuit signal is higher than the allowed or expected range for the current operating conditions. “Circuit High” describes what the module sees electrically at its input (for example, a higher-than-expected voltage or a continuously high logic state). It does not, by itself, identify which component has failed.

Depending on the vehicle design, the park switch input may be a simple on/off signal, a circuit that is pulled up internally and pulled low through the switch in one state, or part of an integrated assembly that provides a park-status signal. Regardless of the design, C0357 indicates that the input is being interpreted as stuck or driven high when it should not be.

Quick Reference

• DTC: C0357
• Official Title: C0357 – Park Switch Circuit High
• Official Meaning: Park Switch Circuit High
• System: Chassis
• Standard classification: ISO/SAE Controlled
• Fault Type: Circuit High
• What it indicates: The park switch circuit input is detected above the expected range (electrically “high”).
• Primary diagnostic direction: Verify whether the signal is being forced high by a short to voltage, an open/high-resistance path that prevents it from going low, a connector/terminal issue, a faulty switch, or (after external checks) a module input concern.

Symptoms

Symptoms depend on how the vehicle uses the park switch signal for chassis logic and safety decisions. Some vehicles may show obvious behavior changes, while others may only store the code.

• Warning indicator or message: A chassis-related warning or service message may appear.
• Incorrect Park status indication: The indicated Park state may not match the actual selector or mechanism position.
• Unexpected interlock behavior: Shift or start enable logic may not operate as intended if Park confirmation is required.
• Feature inhibition: Functions that require a valid Park input may be limited until the input is plausible.
• Intermittent condition: Symptoms may come and go due to harness movement, vibration, or connector contact variation.
• Additional DTCs: Related input, plausibility, or electrical codes may be present depending on system strategy.

Common Causes

C0357 is specifically a circuit high detection. Causes typically fall into faults that add voltage to the signal or prevent the signal from being pulled low when required.

• Short to voltage on the signal circuit: The park switch signal conductor is contacting a powered circuit or B+ source.
• Harness insulation damage: Chafing, pinching, or heat damage allowing cross-feed into the park switch circuit.
• Connector or terminal faults: Corrosion, moisture intrusion, damaged seals, backed-out terminals, spread terminals, or poor terminal tension affecting the input reading.
• Open circuit or high resistance in a return/ground path: If the circuit requires a path to pull the signal low, excessive resistance can leave the module seeing a high state.
• Park switch electrical fault: Switch contacts stuck in the high state or internal failure that results in an abnormally high output/state.
• Control module input fault: Internal pull-up/reference or input conditioning issues can hold the input high after external circuits are verified.
• Power/ground integrity issue affecting interpretation: Abnormal supply or ground conditions can alter how the input voltage is measured or interpreted.

Diagnosis Steps

The goal is to confirm the circuit-high condition and then isolate whether the high reading is caused by the switch, wiring/connectors, power/ground integrity, or the module input. Use the correct wiring diagram, connector views, and pinouts for the exact vehicle configuration.

1. Confirm the code and capture data: Scan all modules for stored and pending DTCs. Save freeze-frame/event data and note whether C0357 is current or history.
2. Identify the monitoring module and circuit details: Determine which module monitors the park switch circuit and which connector pins are involved. Confirm whether the input is discrete, pulled up, or otherwise conditioned per service information.
3. Check for related electrical codes first: Address any codes related to supply voltage, reference voltage, or ground integrity because they can distort input readings and create misleading results.
4. Perform a visual harness inspection: Inspect the harness routing between the park switch and the monitoring module. Look for pinch points, rub-through, heat exposure, prior repair areas, or contact with moving components.
5. Inspect connectors and terminals: Disconnect and inspect the relevant connectors (switch side and module side where accessible). Look for corrosion, moisture, bent pins, terminal push-out, damaged locks, or compromised seals. Repair connection issues before electrical measurements.
6. Use scan tool data to observe the input: If available, monitor the park switch input parameter. Verify whether it remains high regardless of switch position, or if it changes intermittently.
7. Measure signal voltage at the appropriate points: Back-probe at the module input and (where applicable) at the switch output. Compare the measured values to the expected high/low thresholds in service information. A continuously high voltage suggests a short to voltage or loss of a pull-down path (depending on design).
8. Isolate the switch from the circuit: Disconnect the park switch (or the component that contains it) and recheck the signal at the module side:
   • If the signal stays high with the switch disconnected, suspect a short to voltage in the harness or an internal module input issue.
   • If the signal drops to a normal value when disconnected, suspect the switch or the portion of wiring between the disconnect point and the switch.
9. Test for short-to-voltage: With power off as required by the service procedure, check for unwanted continuity between the signal circuit and voltage sources. Manipulate the harness during testing to reveal intermittent contact.
10. Check the circuit for opens/high resistance: Measure end-to-end continuity and resistance of the signal circuit and any related return/ground circuit. Inspect splices or junction points if the diagram indicates they are present.
11. Verify ground/return integrity under load: Where applicable, perform voltage drop testing on the ground/return path while the circuit is loaded. Excessive voltage drop can prevent the signal from achieving a valid low state.
12. Evaluate the module input only after external verification: If the switch and wiring test within specification and the input still reads high, follow service pin tests to confirm whether the module’s input stage is faulty.
13. Clear and recheck: Clear the DTC(s), operate the system through the conditions required to run the monitor, and confirm the park switch input transitions correctly and C0357 does not reset.

Possible Fixes

Repairs should be based on test results that confirm the source of the circuit-high condition.

• Repair short-to-voltage wiring faults: Restore damaged insulation, correct routing issues, and repair any cross-fed sections of the park switch signal circuit.
• Restore connector/terminal integrity: Correct terminal fitment issues, repair terminal damage, address moisture intrusion, and ensure connectors are properly seated and locked.
• Repair open circuits or high resistance: Fix opens or excessive resistance in the signal circuit and any required return/ground path that prevents a valid low state.
• Correct power/ground integrity issues: Repair affected power feeds, fuses, grounds, or shared circuits if testing shows the input reading is influenced by supply/ground problems.
• Replace the park switch (or the integrated component containing it): Only when testing confirms the switch cannot produce correct electrical states and is responsible for the high reading.
• Service the control module: Reprogram or replace only after verifying the switch and external circuitry and completing service pin tests that support an internal input fault.

Can I Still Drive With C0357?

C0357 means the vehicle is detecting a high electrical state on the park switch circuit. Because Park status can affect safety logic, drivability and risk depend on what functions rely on this signal and what symptoms are present.

• If the vehicle operates normally: Driving may be possible, but diagnosis should not be delayed because a circuit-high condition can be intermittent and may progress into loss of Park confirmation or interlock-related problems.
• If Park indication is incorrect or interlocks are abnormal: Treat it as a safety concern. Do not rely on the indicated Park state, and avoid continued operation until the circuit-high condition is diagnosed and corrected.

Repair Costs

Repair cost depends on whether the confirmed root cause is wiring, connector condition, a switch or module issue, or the labor needed to diagnose the fault correctly.

Last updated: March 26, 2026

Is C0357 an ISO/SAE controlled code?

Yes. C0357 is classified as ISO/SAE Controlled and belongs to the Chassis system.

Does C0357 identify a specific failed part?

No. C0357 reports the condition Park Switch Circuit High. A circuit-high fault describes what the module detects electrically; it does not, by itself, prove whether the cause is the switch, wiring/connectors, a short-to-voltage, a return/ground issue, or a module input concern.

What should be checked before replacing the park switch?

Confirm the circuit-high condition with scan data and/or voltage measurements, then check for:

• Signal circuit damage or a short-to-voltage
• Connector/terminal problems that could bias the input high
• Open/high resistance in any required return/ground path

If the signal remains high with the switch disconnected, focus on wiring/connector faults or the module input rather than the switch itself.

Can low battery voltage cause C0357?

C0357 specifically indicates a high condition on the park switch circuit. While power/ground integrity problems can affect how inputs are interpreted, the code definition remains an electrically high reading on that circuit. Address any confirmed power or ground integrity issues found during testing.

What confirms the repair?

The repair is confirmed when the park switch input transitions correctly between expected states and C0357 does not return after clearing codes and completing the applicable functional check.