P0373 - OBD Trouble Code

<<See All OBD Codes

Diagnostic Trouble Code P0373 is defined as Timing Reference High Resolution Signal an Intermittent/Erratic Pulses. This code is detected when some high-resolution pulses are intermittent from the optical sensor to the PCM. The “A” refers the area of the system circuitry than to a particular component in your vehicle. Due to this code you may start facing problems like engine misfire, decreased fuel mileage, engine misfire etc. It is recommended to solve this code on time else can lead to serious problems fairly quickly.

OBD-II Code Decreased engine performance is defined as a Timing Reference High Resolution Signal "A" Intermittent/Erratic. It means that your powertrain control module (PCM) has detected an irregularity in the high-resolution timing reference signal. When PCM detects an abnormality in the high-resolution timing reference signal and variations in the high-resolution engine timing signal that exceed a predetermined number of degrees, a code will be stored and a service engine soon lamp may be illuminated. However, the maximum allowable number of degrees of variation may differ between manufacturers, vehicle lines, engine sizes/types, and transmission applications. There are approximately 64 high resolution pulses for every cam pulse. The severity of this code is moderate to severe.

A code P0373 is set when the PCM detects the engine position sensor "A" is producing a signal with intermittent/erratic pulses.

What causes this problem with the Timing Reference High Resolution Signal A Intermittent/Erratic Pulses?

• Damaged Sensor (camshaft sensor, crankshaft sensor or distributor position sensor)
• Damaged Wiring
• Failed PCM
• Poor Electrical Connection
• Damaged Reluctor Wheel
• Substandard Oil

1. Powertrain Control Module - A powertrain control module, abbreviated PCM, is an automotive component, a control unit, used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit (TCU). This is the one of the most crucial part of your vehicle. If it is malfunctioned, repair or replace as required on priority basis.
2. Distributor Position Sensor - As Faulty crankshaft and camshaft sensors plays a vital role in setting this code so do this distributor position sensor. Ensure its proper functionality to avoid all the associated codes.
3. Crankshaft Position Sensor - A crank sensor is an electronic device used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. A faulty crankshaft sensor will always be a hindrance in the smooth running of your vehicle.
4. Camshaft Position Sensor - The task of the camshaft sensor is to work with the crankshaft sensor to define the exact position of the crankshaft drive. Through the combination of both sensor signals, the engine control unit knows when the first cylinder is in the top dead point. Always replace the frayed camshaft sensor to avoid the associated codes.

Please note that it may take a while before your service engine light comes on, so it is important to recognize these other symptoms ahead of time. Knowing these symptoms will help you fix it quickly.

• Reduced engine performance
• Difficulty in starting engine
• Decreased fuel mileage
• Spark knocking while acceleration
• Illuminated check engine light

P0373 is a one of the serious trouble codes. It is difficult to fix and requires expensive and specialized diagnostic tools. It may be a complicated issue to solve and require you to replace several components, which is time consuming and frustrating if you do not have the proper training and tools. So, it is recommended to seek help of a trained mechanic to fix it. Repairs and replacements that can help you fix this code are as follows:

• Replace the faulty sensors (camshaft sensor, crankshaft sensor or distributive hall-effect sensor)
• Inspect your distributor for excessive side-to-side wobble and endplay.
• Replace the broken or worn-out distributor

On Parts Avatar Canada you will find all the required components that can help you fix this code at the best possible price. We are just a click away, check out our web filled with high grade products.

Here are some steps which you should follow in order to diagnose this P0373 fault code:

• Verify your crankshaft position sensor to check for an engine RPM signal when the engine is cranked or running by using scanner or a tachometer.
• If in case you do not detect an RPM signal, then visually inspect the crankshaft position sensor, crankshaft gear, and sensor connector for damage and signs of repair.
• Test the CPS system for a reference voltage signal (typically five-volts).
• Check for system continuity using your digital volt/ohmmeter.
• Disconnect the electrical connector from the PCM before using your ohmmeter on the harness side of the circuit.

Common Mistakes When Diagnosing the P0373 Code

The most common mistake while diagnosing this code is unnecessary replacement of crankshaft, camshaft, and distributor sensors, when mechanical distributor failure is the main cause setting this code.