AutoCodes – GMC – P037B GMC

P037B GMC 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 GMC 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 359

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

What does this mean?

What are the Possible Causes of the DTC P037B GMC?

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 GMC?

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 GMC 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 GMC code?

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

Need Help with the Code?

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Information for Specific GMC Models

P037B 2014 GMC Sierra — Wait To Start Indicator Control Circuit High Voltage
P037B 2015 GMC Sierra — Wait To Start Indicator Control Circuit High Voltage
P037B 2016 GMC Sierra — Wait To Start Indicator Control Circuit High Voltage
P037B 2017 GMC Sierra — Wait To Start Indicator Control Circuit High Voltage
P037B 2018 GMC Sierra — 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 GMC Code

1. What does the OBDII code P037B mean on a GMC vehicle?

P037B indicates a high voltage issue in the Wait to Start Indicator Control Circuit, which is part of the system that communicates with the glow plug system in diesel engines.

2. What are the common symptoms of a P037B code?

Symptoms may include a malfunctioning or unresponsive "Wait to Start" indicator light, extended engine cranking times, or difficulty starting the engine in cold conditions.

3. What causes the P037B code to appear?

Common causes include a faulty Wait to Start indicator light, a shorted or open circuit in the wiring, a damaged control module, or corroded electrical connections.

4. Can I drive my GMC vehicle with a P037B code?

While the vehicle may still be drivable, ignoring this code could lead to starting difficulties, particularly in colder weather, and may result in additional stress on the glow plug system.

5. How can I diagnose the P037B code?

Start by visually inspecting the wiring and connectors for damage or corrosion. Next, use a multimeter to check for proper voltage and continuity in the Wait to Start circuit.

6. What repairs are typically needed to fix the P037B code?

Repairs may include replacing the Wait to Start indicator light, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming/replacing the control module if necessary.

7. How much does it cost to fix the P037B code on a GMC?

Repair costs can vary, but minor fixes like repairing wiring or replacing the indicator light may cost $50-$150. If a control module replacement is needed, costs could exceed $500.

8. Can a bad glow plug system trigger the P037B code?

While the glow plug system itself may not directly cause this code, issues with the system can indirectly affect the Wait to Start indicator circuit.

9. Will resetting the code fix the issue?

Clearing the code without addressing the underlying problem will only temporarily remove the warning. The code will likely return until the issue is properly resolved.

10. Can a failing PCM cause the P037B code?

Yes, a failing Powertrain Control Module (PCM) or Engine Control Module (ECM) can potentially cause this code if it fails to properly regulate voltage in the Wait to Start circuit.