Fix P0335: Mechanic’s solutions that WORKED

The code P0335: Crankshaft Position Sensor “A” Circuit Malfunction indicates a malfunction in the Crankshaft Position Sensor “A” Circuit. This fault is typically caused by issues with the sensor itself, its wiring, or the engine control module. It’s a critical sensor for engine operation, as it provides essential timing information for fuel injection and ignition.

P0335 quick overview

Meaning	P0335: Crankshaft Position Sensor “A” Circuit Malfunction
Is it serious?	Yes, it can lead to engine performance issues, including no-start conditions.
Possible causes	– Faulty crankshaft position sensor – Damaged wiring or connectors – Faulty ECM/PCM – Misaligned or damaged tone ring – Poor electrical connections – Faulty reference voltage or ground
How to diagnose?	1. Verify the code with an OBD2 scanner. 2. Visually inspect the crankshaft position sensor and wiring. 3. Check the crankshaft position sensor’s reference voltage and ground. 4. Use an oscilloscope to check the crankshaft sensor signal. 5. Inspect the engine timing components. 6. Consider the possibility of a faulty ECM/PCM. 7. If necessary, replace the crankshaft position sensor.

How to fix P0335 – learn from mechanics

I looked into P0335 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Nissan

Vehicle Information 1999 Nissan Sentra XE, 1.6L

Issue + Repair History

• Slowly flashing MIL light
• No codes present, but data stream showing irregular values (ECT -40, fuel trim -100, no RPM reading)
• History of P0335 crank sensor code, replaced with updated factory sensor
• Wiring to ECM checked, new distributor assembly tested, timing and variable valve timing operation checked
• Problem persisted for 4-5 years, vehicle ran fine but couldn’t pass emissions due to flashing check engine light

What Are People Suggesting to Fix Issue

• Replace ECM, as it might not be responding to basic inputs
• Check for open circuit in ECT
• Inspect timing chain sprocket for wear and tensioner position
• Check power and grounds to PCM before replacement
• Consider replacing all three engine speed sensors (front cam, rear cam, & crank) as a kit
• Perform basic checks like cylinder balance test

What Was the Final Fix Replacing the ECM fixed both the flashing MIL light and the persistent P0335 code.

Case #2: BMW

Vehicle Information 2008 BMW 528xi, 3.0L

Issue + Repair History

• MIL light on, low power
• Long crank time (about 5 seconds before starting)
• Codes P0335 and P1727 set immediately after resetting controllers

What Are People Suggesting to Fix Issue

• Scope the crank sensor to check its condition
• Inspect wiring under crank sensor boot for potential shorting
• Replace crank sensor with an OEM part

What Was the Final Fix Replacing the crank sensor fixed the issue.

Case #3: Chevrolet

Vehicle Information 2002 Chevrolet Express 3500 LS, 8.1L

Issue + Repair History

• No start condition
• Code P0335B (CKP Sensor A Circuit)
• Replaced cam and crank sensors
• Multiple ECM replacements and flashes
• Inspected wiring and tone wheel on crank
• Found damaged tone rings and pieces of old sensor in oil pan

What Are People Suggesting to Fix Issue

• Check ignition signal and wiring from PCM
• Trace all wiring for potential damage or shorts
• Ensure security light is going out
• Check for unrelated short circuits, like O2 sensors
• Inspect coil wiring harness for broken wires

What Was the Final Fix The final fix involved removing the transmission and engine oil pan, extracting the crankshaft, and finding pieces of the old sensor in the pan. The tone rings were damaged, likely from previous attempts to remove the sensor. New tone rings were installed, and after reassembling the engine, the truck started and ran well following a crank relearn.

Case #4: Honda

Vehicle Information 1998 Honda Accord EX, 3.0L

Issue + Repair History

• Car towed in for not starting
• Code P0335A (Crank Sensor A Circuit Malfunction)
• Immobilizer key light blinking
• Engine hesitation at about 3000 RPM
• Issue resolved by properly pushing in the crank sensor socket

What Are People Suggesting to Fix Issue

• Check EGR passages for clogging
• Inspect crank sensor wires and mounting
• Ensure sensor and ring are clean and air gap is within spec
• Consider replacing the crank sensor if other checks are fine

What Was the Final Fix The problem was resolved by properly pushing in the crank sensor socket, which had not been done correctly by the previous owner’s mechanic.

Case #5: Volvo

Vehicle Information 1999 Volvo S80 T6, 2.8L

Issue + Repair History

• Car towed in, no start condition
• Code P0335 (Crank Sensor Position A)
• No spark detected
• Issue resolved by replacing the crank sensor

What Are People Suggesting to Fix Issue

• Check reference voltage and ground to sensor
• Lab scope signal wire should show a sinewave with a missing tooth design
• If no RPM on scan tool while cranking, a crank sensor replacement is likely needed
• Check resistance across sensor pins
• Try disconnecting battery and holding cables together for a reset

What Was the Final Fix The problem was fixed by replacing the crank sensor.

Advice	Description of Diagnostic Step
Check Crank Sensor	Inspect the crank sensor for damage, proper installation, and connection.
Scope Crank Sensor Signal	Use an oscilloscope to check the waveform of the crank sensor signal during cranking.
Check Wiring and Connectors	Inspect the wiring and connectors for damage, corrosion, or loose connections.
Check ECM/PCM	Consider the possibility of a faulty Engine Control Module (ECM) or Powertrain Control Module (PCM).
Check Reference Voltage and Ground	Verify that the crank sensor is receiving the correct reference voltage and has a good ground connection.
Replace Crank Sensor	If diagnostics point towards a faulty sensor and all other checks are normal, replace the crank sensor.
Check for Additional Codes	Look for other OBD2 codes that might be related to the P0335 code to get a better understanding of the issue.
Check Engine Timing Components	Inspect the timing belt, tone ring, and related components for damage or misalignment.