Fix P0322: Mechanic’s solutions that WORKED

The OBD2 code P0322 is a diagnostic trouble code (DTC) that points to an issue with the ignition/distributor engine speed sensor, indicating that the sensor is not sending a signal to the Engine Control Module (ECM). This is critical for vehicles as the ECM uses this signal to determine the engine’s timing for optimal performance and fuel efficiency. When this signal is missing, it can lead to a range of problems, including no-start conditions, stalling, and poor engine performance.

P0322 quick overview

Meaning	P0322: Ignition/Distributor Engine Speed Sensor No Signal
Is it serious?	Yes, this code can prevent your vehicle from starting or cause it to stall unexpectedly, which can be dangerous in certain driving situations.
Possible causes	– Faulty engine speed sensor – Damaged wiring or connectors to the sensor – Issues with the ignition/distributor components – Malfunctioning ECM
How to diagnose?	Inspect the engine speed sensor and its connections for damage. Check the wiring and connectors for breaks, shorts, or corrosion. Test the sensor’s functionality using a multimeter or diagnostic scanner. Evaluate the ignition/distributor components for faults. Assess the ECM for any signs of failure or communication issues.

How to fix P0322 – learn from mechanics

I looked into P0322 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: Volkswagen

Vehicle Information:
1998 Volkswagen Cabrio 2.0L

Issue + Repair History:

• Vehicle experiences no start after a long ride, but starts after 15 to 20 minutes of waiting.
• Replaced secondary plugs, cap, rotor, ignition coil module assembly, and wires.

Other OBD2 Codes + Test Results:

• OBD2 Code: P0322 (Ignition/Distributor Engine Speed Inspection No Signal)

Mechanic Suggestions:

• Visit website for manufacturer codes and definitions.
• Check and replace the check valve at the fuel reservoir.
• Inspect the engine speed sensor.
• Verify the presence of an oil viscosity sensor in the sump.

Final Fix:

• Replaced crank sensor, which resolved the issue.

Case #2: Volkswagen

Vehicle Information:
2006 Volkswagen Jetta TDI 1.9L

Issue + Repair History:

• Experiences no start, poor idle quality, MIL lamp on.
• Glow plug light flashes, low oil warning lamp blinks, long crank time.
• Replaced RPM speed sensor due to open resistance.
• Timing belt replaced a few weeks ago.
• Customer indicates the issue progressively worsened.

Other OBD2 Codes + Test Results:

• OBD2 Codes: P0726 (Engine RPM Input Circuit), P0322 (Engine Speed Sensor)

Mechanic Suggestions:

• Consider using OEM sensors, as new sensors may be faulty.
• If problem persists, scope the sensor output and compare it with the sensor input to the ECM.

Final Fix:

• Discovered a broken purple signal wire from the RPM sensor in the main wiring harness on the front of the engine.
• Suspected manual transmission linkage movement caused the wire breakage.
• Rerouted the harness from the original factory position, which resolved the issue.

Case #3: Audi

Vehicle Information:
2000 Audi A4 1.8L

Issue + Repair History:

• Check engine and EPC lights are on.
• Codes P0321 and P0322 related to engine speed sensor detected.
• Sensor tested, appeared to be functioning correctly.
• Engine stalled momentarily while decelerating and braking, then restarted.
• Check engine and EPC lights returned, along with the same codes.
• Car unable to rev over 4000 RPMs and sluggish on takeoff.

Other OBD2 Codes + Test Results:

• OBD2 Codes: P0321 (Engine Speed Sensor Implausible Signal), P0322 (Engine Speed Sensor No Signal)
• Test Results:
  • Ohmed speed sensor pin 2 to 3: 988 ohms (spec = 730-1000 ohms)
  • Speed sensor pin 1 to 2: no continuity
  • Speed sensor pin 1 to 3: no continuity

Mechanic Suggestions:

• Inspect the harness and connector for any issues; if all looks good, replace the sensor.
• Install a new engine speed sensor, as the problem could be erratic.
• Monitor the sensor with a lab scope while driving to watch for dropouts.
• Verify the speed signal waveform while driving to confirm if it’s the actual problem.
• Consider replacing the crank sensor, as it may have intermittent issues when hot despite checking fine when cold.

Final Fix:

• Replaced the crank sensor with a new one, resolving the issue despite the old sensor checking fine when cold.

Diagnostic Step	Brief Explanation
Inspect the engine speed sensor	Look for physical damage or signs of wear.
Check the wiring and connectors	Ensure there are no breaks, shorts, or corrosion.
Test the sensor’s functionality	Use diagnostic tools to verify the sensor’s operation.
Evaluate ignition/distributor components	Check for any related issues that might cause sensor failure.
Assess the ECM	Determine if the ECM is functioning correctly and communicating properly.

The service cases from Volkswagen, Audi, and another Volkswagen model showcase a common issue with the engine speed sensor leading to P0322 codes. Whether it was due to faulty sensors, damaged wiring, or the need for precise diagnostics to identify hidden problems, the resolution often involved replacing the sensor or repairing the wiring. These cases highlight the importance of thorough inspection and diagnostics to ensure that the correct problem is addressed, restoring the vehicle’s performance and reliability.