AutoCodes – Generic – P0373

P0373 Code - Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses

Quick Answer

The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. Common causes include Timing Reference Optical Sensor harness is open or shorted, Timing Reference Optical Sensor circuit poor electrical connection, Faulty Timing Reference Optical Sensor. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0373 indicates Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses.
Common causes: Common causes include Timing Reference Optical Sensor harness is open or shorted, Timing Reference Optical Sensor circuit poor electrical connection, Faulty Timing Reference Optical Sensor.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 13,449

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0373 Description

The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. The high resolution is one of the most important inputs by the PCM for fuel control and timing. This test monitors the number of high resolution pulses which have been missed (not detected). It's based on a comparison between the number of pulses that were detected since the last pump cam pulse and the number of the pulses that should have occurred. There are approximately 64 high resolution pulses for every cam pulse.

OBDII Code P0373 - Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses - AutoCodes.com — P0373 Code - Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses

What does this mean?

What are the Possible Causes of the DTC P0373?

Timing Reference Optical Sensor harness is open or shorted
Timing Reference Optical Sensor circuit poor electrical connection
Faulty Timing Reference Optical Sensor
Damaged Powertrain Control Module (PCM)

How to Fix the DTC P0373?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0373 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0373 code?

Need more information on how to fix the P0373 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0373 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0373 BMW — Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses
P0373 Mercedes-Benz — Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses
P0373 MINI — Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses
P0373 Volkswagen — Timing Reference High Resolution Signal 'A' Intermittent/Erratic Pulses

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0373 Code

1. What are common symptoms of OBDII code P0373?

Symptoms may include engine misfires, rough idling, decreased fuel efficiency, and difficulties starting the vehicle.

2. What causes the OBDII code P0373 to trigger?

The code is usually triggered by intermittent or erratic signals from the high-resolution timing reference sensor 'A', which can be caused by sensor malfunctions, wiring issues, or engine timing problems.

3. How can I diagnose the issue related to OBDII code P0373?

Diagnosis typically involves checking the wiring and connections of the timing reference sensor 'A', testing the sensor itself, and ensuring proper engine timing.

4. Can a faulty crankshaft position sensor trigger code P0373?

Yes, a faulty crankshaft position sensor can sometimes cause intermittent or erratic signals that trigger OBDII code P0373.

5. Is it safe to continue driving with OBDII code P0373 active?

It is not recommended to drive with this code active, as it can lead to potential engine performance issues and further damage if left unresolved.

6. How can I repair OBDII code P0373?

Repair options include replacing the high-resolution timing reference sensor 'A', repairing or replacing damaged wiring, ensuring proper engine timing, and clearing the error code.

7. Can a DIY enthusiast fix OBDII code P0373 at home?

Depending on the level of expertise, DIY enthusiasts may be able to diagnose and repair the issue causing OBDII code P0373, such as replacing the sensor or fixing wiring problems.

8. Will resetting the error code make OBDII code P0373 go away permanently?

Resetting the error code without addressing the underlying issue will not make OBDII code P0373 go away permanently. The root cause of the problem must be identified and fixed.

9. How important is it to address OBDII code P0373 promptly?

It is crucial to address the code promptly to prevent potential engine performance issues, reduced fuel efficiency, and further damage to the vehicle.

10. Can extreme weather conditions affect the occurrence of OBDII code P0373?

Extreme weather conditions, particularly temperature fluctuations, can sometimes affect the occurrence of erratic or intermittent signals that trigger OBDII code P0373.