P0335 Crankshaft Position Sensor Multimeter Continuity Test Steps for No Crank No Start

You turn the key and nothing happens. No crank, no start, and your scan tool throws a P0335 code. That code points to the crankshaft position sensor circuit, and before you spend money replacing parts, you need to know if the wiring or the sensor itself is the problem. A multimeter continuity test is the fastest way to narrow it down in your own garage, and that's exactly what this walkthrough covers.

What Does a P0335 Code Actually Mean?

P0335 stands for "Crankshaft Position Sensor 'A' Circuit Malfunction." The engine control module (ECM) expects a clean signal from the crankshaft position sensor every time the engine rotates. When that signal drops out, gets noisy, or disappears entirely, the ECM sets P0335. On many vehicles especially GM, Nissan, and Toyota models a failed sensor circuit means the ECM won't fire the injectors or ignition coils, resulting in a no crank or no start condition.

The sensor itself reads a reluctor ring on the crankshaft and converts that rotation into a voltage signal. If the ECM can't see that signal, it has no idea where the crankshaft is in its rotation, so it protects the engine by shutting fuel and spark down completely.

Why Does a P0335 Code Cause a No Crank No Start?

Not every P0335 code causes a no-crank situation. In some cases the engine cranks but won't fire up. But when the sensor circuit fails hard a broken wire, a dead short, or a completely failed sensor some vehicle platforms won't even engage the starter. The ECM communicates with the body control module or immobilizer, and without a crank signal, the system refuses to allow starting.

On GM trucks and SUVs, this is especially common. If you're dealing with a Chevrolet or GMC showing this exact scenario, our GM crankshaft position sensor resistance measurement procedure covers the specific resistance specs and connector pinouts for those vehicles.

What Tools Do You Need to Test for P0335?

Digital multimeter one that reads resistance (ohms), DC voltage, and has a continuity/beep mode
Vehicle-specific wiring diagram you need to know which pins are signal, ground, and reference voltage
Back-probe pins or T-pins to test the connector without damaging the terminals
Scan tool (optional but helpful) to clear codes after the repair and confirm live crank signal data
Basic hand tools to access and unplug the sensor

Where Is the Crankshaft Position Sensor Located?

Location varies by engine. Common spots include:

Front of the engine near the crankshaft pulley or harmonic balancer, reading the reluctor ring behind it
Rear of the engine near the flywheel/flexplate, often on the engine block or transmission bell housing
Side of the engine block reading a reluctor integrated into the crankshaft itself

Check a repair manual or reliable forum thread for your specific year, make, and model before you start pulling parts apart.

How to Do a Multimeter Continuity Test on the Crankshaft Position Sensor Wiring

Step 1: Disconnect the Sensor Connector

Unplug the electrical connector from the crankshaft position sensor. You'll typically find a tab or locking clip. Press it and pull gently don't yank the wires.

Step 2: Identify the Pins

A crankshaft position sensor usually has three wires:

Reference voltage (5V or 12V) supplied by the ECM
Signal return sends the pulsing signal back to the ECM
Ground sensor ground back to the ECM

Some two-wire sensors use a signal and ground only (AC-generating type). Know which type you have before testing.

Step 3: Test Continuity from the Sensor Connector to the ECM Connector

Set your multimeter to continuity mode (the symbol that looks like a sound wave or diode). Then:

Back-probe the signal pin at the sensor connector with one multimeter lead.
Go to the ECM connector and find the matching signal pin using your wiring diagram.
Touch the other multimeter lead to that ECM pin.
A beep or near-zero ohm reading confirms the wire is intact. An OL (open loop) reading means the wire is broken somewhere between the sensor and the ECM.

Repeat this for the ground wire and the reference voltage wire. All three should show continuity.

This step catches broken wires, corroded terminals, and pinched harness sections that a visual inspection would miss. For a deeper comparison of sensor types and how to tell them apart with a multimeter, see our guide on crankshaft vs. camshaft sensor multimeter diagnosis.

Step 4: Check for Shorts to Ground

With the connector still unplugged, put one lead on the signal wire and the other on a clean chassis ground. You should get no continuity (OL). If you get a beep, the signal wire is shorted to ground somewhere in the harness and that's your P0335 cause.

Do the same test between the signal wire and the reference voltage wire. No continuity should exist between them either.

Step 5: Test for Shorts to Power

Reconnect the battery (if you disconnected it), turn the key to the ON position, and back-probe the signal wire at the sensor connector. You should not see a steady 5V or 12V on the signal wire with the engine off. If you do, there's a short to power in the harness.

How to Test the Sensor Itself with a Multimeter

Resistance Test

Set your multimeter to ohms (Ω). Measure across the sensor's signal and ground pins at the sensor body itself. A typical reading for a Hall-effect sensor is between 200 and 1,500 ohms, but always confirm with your vehicle's service manual. An open (OL) reading means the internal coil or circuit is dead replace the sensor.

If you need model-specific resistance ranges, our P0335 voltage and resistance readings guide lists common specs across popular engines.

Voltage Output Test (Engine Cranking)

Reconnect the sensor, then back-probe the signal wire. Switch the multimeter to AC voltage for a two-wire magnetic sensor or DC voltage for a three-wire Hall-effect sensor. Have a helper crank the engine. You should see the voltage pulse typically 0.5V to 5V AC fluctuating on a magnetic sensor, or a pulsing 0–5V DC signal on a Hall-effect sensor. No fluctuation during cranking confirms a bad sensor.

Common Mistakes When Diagnosing P0335

Skipping the wiring test and just throwing a new sensor at it. A new sensor won't fix a broken wire or corroded connector.
Testing continuity with the battery connected. Always disconnect the battery before continuity testing to avoid damaging the multimeter or ECM.
Not checking the reluctor ring. A damaged, cracked, or missing tooth on the reluctor ring can cause an intermittent P0335 even with a good sensor and wiring.
Ignoring the connector itself. Push the pins gently with a pick. Loose, spread, or corroded pins are a hidden cause of circuit malfunction codes.
Assuming P0335 always means the sensor is bad. About half the time on GM vehicles, the wiring harness near the exhaust manifold melts or rubs through, breaking the circuit.

What If the Sensor and Wiring Both Test Good?

If your sensor resistance is in spec, continuity is solid on all three wires, and there are no shorts, the problem may be:

ECM failure the internal driver for the crank signal circuit may be damaged
Reluctor ring damage inspect it visually if accessible
Timing chain or belt jump if the crank and cam are out of sync, the ECM may flag P0335 alongside P0016 or similar codes
Intermittent connection wiggle the harness while monitoring live data on a scan tool to catch a drop-out

Quick Diagnostic Checklist for P0335 No Crank No Start

Read and record all codes note any companion codes like P0340 (camshaft sensor)
Visually inspect the sensor connector, harness, and routing for damage
Unplug the sensor and test wiring continuity from sensor to ECM on all three pins
Test for shorts to ground and shorts to power on the signal wire
Measure sensor resistance at the sensor body compare to factory spec
Reconnect and crank-test for voltage output on the signal wire
Inspect the reluctor ring if accessible
Check connector pins for corrosion, spread terminals, or push-back
If everything passes, suspect the ECM or an intermittent fault
Clear codes and verify the fix with a road test

Tip: Before you start any of these tests, photograph the sensor connector and its pin positions. Wiring diagrams are helpful, but a photo of the actual connector on your exact engine eliminates pin-identification errors the number one reason DIYers get false test results.