AutoCodes – Generic – P037B

P037B Code - Wait To Start Indicator Control Circuit High 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: P037B indicates Wait To Start Indicator Control Circuit High 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 528

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 P037B 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 voltage on the Wait To Start Indicator Control circuit for greater than 1 s.

OBDII Code P037B - Wait To Start Indicator Control Circuit High Voltage - AutoCodes.com — P037B Code - Wait To Start Indicator Control Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P037B?

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 P037B?

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 P037B 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 P037B code?

Need more information on how to fix the P037B code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Makes

P037B Chevrolet — Wait To Start Indicator Control Circuit High Voltage
P037B GMC — Wait To Start Indicator Control Circuit High 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 P037B Code

What does the OBDII code P037B mean?

1. P037B indicates a high voltage issue in the Wait to Start Indicator Control Circuit, which is typically related to diesel engines during the preheating phase for the glow plugs. 2.

What are the symptoms of the P037B code?

Common symptoms include the "Wait to Start" indicator not functioning properly, extended engine cranking times, or difficulty starting the engine in cold conditions. 3.

What causes the P037B code to trigger?

The code can be caused by a faulty "Wait to Start" indicator lamp, damaged wiring, corroded electrical connections, or a malfunctioning engine control module (ECM). 4.

Can I still drive my vehicle with a P037B code?

Yes, you can usually drive the vehicle, but starting it in cold weather may be difficult. Prolonged issues with the glow plug system can lead to engine damage. 5.

How can I diagnose the P037B code?

Diagnosis involves checking the "Wait to Start" indicator lamp, inspecting the wiring and connectors for damage or corrosion, and using a multimeter to test circuit voltage. 6.

How is the P037B code fixed?

Repairs may include replacing the indicator lamp, repairing or replacing damaged wiring or connectors, or reprogramming/repairing the ECM if necessary. 7.

How much does it cost to fix the P037B code?

Repair costs vary. Replacing a faulty indicator lamp may cost $50â€“$100, while wiring repairs or ECM replacement can be significantly more expensive, ranging from $200â€“$1,000 or more. 8.

Can a dead battery cause the P037B code?

While unlikely, a weak or dead battery may indirectly contribute to electrical issues that could impact the Wait to Start Indicator Control Circuit. 9.

Will clearing the P037B code with a scan tool fix the problem?

Clearing the code may temporarily reset the warning, but the underlying issue must be addressed to prevent the code from returning. 10.

Can a faulty glow plug cause the P037B code?

A faulty glow plug itself is not the direct cause of the P037B code, but issues in the glow plug system can sometimes contribute to related circuit problems.