P2357 – Cylinder 6 Knock Sensor Circuit

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit | Location: Cylinder 6

Definition source: SAE J2012/J2012DA (industry standard)

DTC P2357 indicates the powertrain controller has detected an electrical circuit fault related to the cylinder 6 knock sensor circuit. A knock sensor circuit issue is about the integrity of the sensor’s wiring and signal path (not a guaranteed mechanical engine knock condition). When this code sets, the controller may limit spark advance or change ignition strategy to protect the engine, which can affect performance. Exact monitoring logic, enabling conditions, and diagnostic thresholds vary by vehicle, so always confirm connector views, pin functions, and test specifications in the correct service information for your application.

What Does P2357 Mean?

P2357 means Cylinder 6 Knock Sensor Circuit. Under the SAE J2012 DTC framework, the code format identifies this as a powertrain-related diagnostic that points to an electrical problem in the circuit associated with the knock sensor input designated for cylinder 6. In practice, the controller is flagging that the expected knock sensor circuit signal or electrical integrity is not valid according to its internal circuit checks. Because this is a circuit-type fault, diagnosis should focus on wiring, connectors, power/ground integrity (as applicable), and the sensor-to-controller signal path before considering component replacement.

Quick Reference

  • System: Powertrain
  • Official meaning: Cylinder 6 Knock Sensor Circuit
  • Standard: ISO/SAE controlled
  • Fault type: Circuit
  • Severity: MIL may illuminate and performance may be reduced due to conservative ignition control; immediate safety impact is uncommon unless drivability becomes unstable.

Symptoms

  • MIL/Check Engine: Warning light illuminated and P2357 stored as an active or history code.
  • Reduced power: Noticeable drop in acceleration due to protective ignition timing adjustments.
  • Poor fuel economy: Increased consumption from less efficient combustion strategy.
  • Roughness: Mild hesitation, surge, or uneven response under load (varies by vehicle and operating conditions).
  • Pinging concern: Driver may report spark knock sounds, though the DTC alone does not confirm true knock is occurring.
  • Intermittent behavior: Symptoms may come and go with vibration, temperature changes, or after engine service affecting harness routing.

Common Causes

  • Open circuit, short to ground, or short to power in the cylinder 6 knock sensor signal wire
  • Poor connection at the cylinder 6 knock sensor connector (loose fit, backed-out terminal, corrosion)
  • Damage to the knock sensor harness (chafing, pinched wiring, heat damage, previous repair issues)
  • Faulty cylinder 6 knock sensor (internal circuit failure)
  • PCM/ECM connector issues affecting the knock sensor circuit (terminal spread, corrosion, water intrusion)
  • Shared sensor ground or reference issue (where applicable by vehicle design) impacting the knock sensor circuit
  • Improper shielding or broken shield/drain wire on the knock sensor circuit (if the circuit uses shielding)
  • Aftermarket electrical modifications or improper routing near ignition/charging wiring causing electrical interference that the controller interprets as a circuit fault

Diagnosis Steps

Tools typically needed include a scan tool with live data and freeze-frame access, a digital multimeter, and a wiring diagram/service information for the specific vehicle. Depending on sensor type and access, a lab scope can help confirm signal integrity and noise. Basic hand tools for connector access, plus supplies for terminal inspection and repair, are also useful.

  1. Confirm the code and capture context: Scan for DTCs, record freeze-frame data, and note any companion codes (especially other knock sensor, sensor ground/reference, or module power codes). Clear codes and see if P2357 resets immediately or after a drive cycle.
  2. Verify the complaint with live data logging: With the scan tool, monitor available knock-related PIDs while idling and during a short controlled road test (if safe). Log data so you can correlate the fault to RPM/load/temperature, noting whether the signal appears fixed, erratic, or absent (PID availability varies by vehicle).
  3. Perform a focused visual inspection: Inspect the cylinder 6 knock sensor area and harness routing as far as accessible. Look for chafing, pinch points, contact with hot components, oil saturation, and signs of prior repairs. Correct obvious routing or damage concerns before deeper testing.
  4. Check connectors and terminals: Key off. Disconnect the sensor connector and the controller-side connector related to the knock sensor circuit (as service information directs). Inspect for corrosion, moisture, bent pins, terminal push-out, poor pin fit, or damaged seals. Repair terminal issues as needed and ensure connectors latch securely.
  5. Wiggle test for intermittent circuit faults: With the connector(s) reconnected, run the engine (if possible) and gently flex the harness at likely stress points while observing live data and/or DTC status. If the fault triggers during movement, isolate the segment that changes the reading or sets the code.
  6. Check circuit integrity (continuity and shorts): Key off, sensor disconnected. Using the wiring diagram, test continuity of the signal circuit between the sensor connector and the controller connector. Then check for shorts between the signal wire and ground, and between the signal wire and power feeds. Repair opens/shorts found, then re-test.
  7. Voltage-drop test the circuit under load: Where service information allows, load the circuit (using an approved method) and perform voltage-drop testing across suspect sections: connector-to-connector, across terminals, and across splices. Excessive drop indicates high resistance from corrosion, poor crimps, or damaged conductors.
  8. Verify grounds/references that the circuit depends on: If the vehicle design uses shared sensor grounds or a reference/bias feed for the knock circuit, test those at the sensor connector and at the controller connector. Confirm the ground path integrity with a voltage-drop test while the circuit is loaded (exact strategy varies by vehicle).
  9. Evaluate the knock sensor and signal quality: If wiring checks pass, test the knock sensor per service information. If a scope is available, check for a stable, noise-free waveform and for signs of intermittent dropouts when tapping lightly near the sensor mounting area only as the manufacturer permits. Replace the sensor only after confirming the circuit is not the root cause.
  10. Check controller-side connection and decision-making: If the sensor and wiring test good, inspect the controller connector again for terminal tension and any evidence of water intrusion. Confirm related power and ground feeds to the controller are stable. If all external causes are eliminated, follow service information for controller diagnostics and replacement/programming procedures.

Professional tip: Many “circuit” knock-sensor faults are caused by subtle terminal fit issues or harness damage under clamps or brackets. After repairs, repeat the wiggle test and then run a longer live-data log over varied loads to confirm the code does not return and the signal remains stable across conditions.

Need wiring diagrams and factory-style repair steps?

Powertrain faults often require exact wiring diagrams, connector pinouts, and guided test steps. A repair manual can help you confirm the cause before replacing parts.

Factory repair manual access for P2357

Check repair manual access

Possible Fixes & Repair Costs

Repair costs for P2357 can vary widely because the fault is circuit-related and the root cause may be a simple connection issue or a component/wiring problem. Total cost depends on diagnostic time, harness accessibility, and whether parts replacement is actually required after testing.

  • Repair connector issues: Clean corrosion, correct bent pins, restore pin tension, and ensure the knock sensor connector is fully seated and properly locked.
  • Harness repair: Locate and repair damaged wiring (chafing, cuts, heat damage) in the Cylinder 6 knock sensor circuit; re-route and protect as needed to prevent repeat faults.
  • Restore power/ground integrity: Repair shared grounds or reference/signal returns (varies by vehicle) and correct poor splices; verify with voltage-drop testing after repairs.
  • Replace the knock sensor: Replace the Cylinder 6 knock sensor only if circuit checks pass and the sensor fails inspection/testing per service information.
  • Address PCM/ECM connector faults: Repair terminal fitment issues at the control module connector, including fretting or backed-out terminals, when proven by pin tests.
  • Update or reprogram control module (if applicable): Only if service information calls for it and testing confirms no wiring/sensor fault; verify calibration applicability by VIN and system configuration.

Can I Still Drive With P2357?

You can often drive short distances with P2357, but expect the engine control system may limit performance or adjust ignition timing to protect the powertrain. If you notice severe drivability symptoms (hard misfire, stalling, reduced power that affects merging, or warning messages impacting braking/steering systems), do not continue driving—diagnose the knock sensor circuit fault first.

What Happens If You Ignore P2357?

Ignoring P2357 can lead to persistent warning lights and continued protective control strategies that reduce power, fuel economy, and overall drivability. If the control module cannot rely on the Cylinder 6 knock sensor circuit, it may use conservative ignition timing, and ongoing circuit faults can worsen due to vibration, heat, or progressive connector/wiring damage.

Compare nearby cylinder knock trouble codes with similar definitions, fault patterns, and diagnostic paths.

  • P2354 – Cylinder 3 Knock Sensor Circuit
  • P2353 – Cylinder 2 Knock Sensor Circuit
  • P2352 – Cylinder 1 Knock Sensor Circuit
  • P2367 – Cylinder 16 Knock Sensor Circuit
  • P2366 – Cylinder 15 Knock Sensor Circuit
  • P2365 – Cylinder 14 Knock Sensor Circuit

Key Takeaways

  • P2357 is a circuit fault: It indicates an electrical issue in the Cylinder 6 knock sensor circuit, not a confirmed mechanical engine problem by itself.
  • Test before replacing parts: Wiring, terminals, and grounds are common contributors and should be verified with targeted electrical checks.
  • Intermittents are common: Heat, vibration, and harness routing can cause a fault that appears only under certain operating conditions.
  • Protective strategies may occur: The control module may reduce performance by altering timing when knock feedback is unreliable.
  • Service info matters: Circuit design and access vary by vehicle, so connector pinouts and test procedures should be verified before probing.

Vehicles Commonly Affected by P2357

  • Vehicles with V6, V8, V10, or V12 engines: Configurations where individual cylinders are clearly indexed and monitored.
  • Engines using multiple knock sensors: Systems that monitor knock activity by bank, cylinder group, or specific cylinder logic (varies by vehicle).
  • Models with knock sensors mounted in the engine valley: Locations prone to heat soak and difficult harness routing.
  • Vehicles with tight packaging near exhaust components: Higher risk of harness insulation damage from heat exposure.
  • High-mileage vehicles: Greater likelihood of connector fretting, brittle wiring, and degraded terminal tension over time.
  • Vehicles operated in corrosive environments: Increased chances of moisture intrusion and connector corrosion affecting signal integrity.
  • Vehicles with recent engine or intake service: Potential for pinched wiring, missed grounds, or partially seated connectors after repairs.
  • Vehicles with aftermarket electrical modifications: Added grounds, splices, or rerouted harnesses that can introduce resistance or intermittent opens.

FAQ

Does P2357 mean the engine is knocking?

No. P2357 indicates a detected fault in the Cylinder 6 knock sensor circuit. While the knock sensor is used to monitor combustion vibration, this DTC points to an electrical circuit problem unless further testing confirms a related mechanical condition.

Should I replace the knock sensor immediately for P2357?

Not automatically. Because P2357 is a circuit fault, start by checking connector seating, terminal condition, harness damage, and ground integrity. Replace the knock sensor only after circuit tests and service-information checks indicate the sensor itself is faulty.

Can P2357 be caused by wiring even if the connector looks fine?

Yes. Damage can be hidden under loom, near brackets, or where the harness contacts hot or moving parts. High resistance inside a crimp, a partially broken conductor, or poor pin tension can also cause a circuit fault without obvious external damage.

Will clearing P2357 fix the issue?

Clearing the code only resets stored fault information; it does not repair the underlying circuit problem. If the fault is still present, the code will likely return after a drive cycle or when operating conditions repeat. Use clearing only after making repairs or to confirm an intermittent.

What is the most important test for P2357?

Verify circuit integrity end-to-end: confirm the connector and terminals are sound, perform continuity and voltage-drop checks as specified in service information, and use a wiggle test while monitoring live data or scan tool status. This approach helps distinguish a sensor fault from wiring or module-side issues.

After repairs, confirm the fix by clearing codes, running a road test under similar conditions to the original failure, and rechecking for pending or stored faults to ensure the Cylinder 6 knock sensor circuit remains stable.