AutoCodes – Generic – P037A

P037A Code - Wait To Start Indicator Control Circuit Low Voltage

Quick Answer

Ignition voltage is supplied directly to the Wait To Start indicator. Common causes include Faulty Instrument Cluster, Instrument Cluster harness is open or shorted, Instrument Cluster circuit poor electrical connection. 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: P037A indicates Wait To Start Indicator Control Circuit Low Voltage.
Common causes: Common causes include Faulty Instrument Cluster, Instrument Cluster harness is open or shorted, Instrument Cluster circuit poor electrical connection.
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 668

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 17, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P037A Description

Ignition voltage is supplied directly to the Wait To Start indicator. The Engine Control Module (ECM) controls the lamp by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the ECM. When the ECM is commanding a component ON, the voltage of the control circuit should be low, near zero volts. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. The Diagnostic Trouble Code (DTC) will be set when the ECM detects a short to ground on the Wait To Start Indicator Control circuit for greater than 3 s.

OBDII Code P037A - Wait To Start Indicator Control Circuit Low Voltage - AutoCodes.com — P037A Code - Wait To Start Indicator Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P037A?

Faulty Instrument Cluster
Instrument Cluster harness is open or shorted
Instrument Cluster circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P037A?

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 P037A 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 P037A code?

Need more information on how to fix the P037A code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P037A code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P037A Chevrolet — Wait To Start Indicator Control Circuit Low Voltage
P037A GMC — Wait To Start Indicator Control Circuit Low Voltage

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 P037A Code

1. What does the OBDII code P037A mean?

P037A indicates that the Wait To Start Indicator Control Circuit is experiencing low voltage, typically in diesel engines where the glow plug system is used for starting.

2. What are the common symptoms of code P037A?

Symptoms may include the "Wait to Start" indicator not illuminating, difficulty starting the engine, poor engine performance, or a stored check engine light.

3. What causes the P037A code to appear?

Common causes include a faulty wait-to-start indicator bulb, damaged wiring, corroded electrical connections, or a malfunctioning glow plug control module.

4. Can I still drive my vehicle with the P037A code?

While you may be able to drive, starting the engine could become more difficult, especially in cold weather, and ignoring the issue may lead to further damage.

5. How can I diagnose the P037A code?

Begin by inspecting the indicator bulb, wiring, and connectors for damage or corrosion. Test the circuit voltage and check the glow plug control module for faults.

6. What tools are needed to fix the P037A code?

You may need a multimeter to test circuit voltage, a scan tool to clear the code, and basic tools to repair or replace damaged components.

7. How much does it cost to repair the P037A code?

Costs vary depending on the cause, ranging from $50â€“$100 for a simple bulb replacement to $200â€“$400 if the glow plug control module needs replacement.

8. Can a dead battery cause the P037A code?

Yes, a weak or dead battery can cause low voltage in the circuit and trigger the P037A code.

9. How do I prevent the P037A code from reoccurring?

Regularly inspect and maintain the glow plug system, check electrical connections, and ensure the battery is fully charged.

10. Is the P037A code specific to any vehicle brand?

No, P037A is a generic OBDII code, but it is more common in diesel vehicles with a glow plug system. Always refer to your vehicle's service manual for specific details.