AutoCodes – Chevrolet – P1635 Chevrolet

P1635 Chevrolet Code - 5-Volt Reference Circuit Low Conditions

Quick Answer

The Powertrain Control Module (PCM) uses a common 5.0 Volt Reference 1 circuit as a sensor feed. Common causes include A/C Pressure sensor harness is open or shorted, MAP sensor harness is open or shorted, EGR valve harness is open or shorted. 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: P1635 Chevrolet indicates 5-Volt Reference Circuit Low Conditions.
Common causes: Common causes include A/C Pressure sensor harness is open or shorted, MAP sensor harness is open or shorted, EGR valve harness is open or shorted.
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 52,499

How popular is this code, among other codes? Medium

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 Sep 03, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1635 Chevrolet Description

The Powertrain Control Module (PCM) uses a common 5.0 Volt Reference 1 circuit as a sensor feed. This circuit supplies 5 Volts to the following sensors: The Air Condition (A/C) Pressure sensor, the Manifold Absolute Pressure (MAP) sensor, and the Engine Gas Recirculation (EGR) valve. The PCM monitors the voltage on the 5.0 Volt Reference 1 circuit.

OBDII Code P1635 Chevrolet - 5-Volt Reference Circuit Low Conditions - AutoCodes.com — P1635 Chevrolet Code - 5-Volt Reference Circuit Low Conditions

What does this mean?

What are the Possible Causes of the DTC P1635 Chevrolet?

A/C Pressure sensor harness is open or shorted
MAP sensor harness is open or shorted
EGR valve harness is open or shorted

How to Fix the DTC P1635 Chevrolet?

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 P1635 Chevrolet 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.

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Need more information on how to fix the P1635 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1635 Chevrolet code diagnosed by a professional: Find a repair shop in your area

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 P1635 Chevrolet Code

1. What are the common symptoms of OBDII code P1635 Chevrolet?

The common symptoms of P1635 include stalling, rough idling, poor engine performance, and illuminated Check Engine Light.

2. What does the OBDII code P1635 Chevrolet indicate?

P1635 indicates a low voltage condition in the 5-volt reference circuit, which can affect various sensors and components in the vehicle.

3. What are the possible causes of the 5-volt reference circuit low condition (P1635) in a Chevrolet?

Possible causes of P1635 include a faulty 5-volt reference circuit, damaged wiring or connectors, a defective sensor drawing excessive current, or a malfunctioning powertrain control module (PCM).

4. How can I diagnose the OBDII code P1635 in my Chevrolet?

Diagnosing P1635 involves checking the 5-volt reference circuit for continuity, inspecting wiring and connectors for damage, testing sensors for proper operation, and scanning the PCM for related fault codes.

5. Can driving with the OBDII code P1635 Chevrolet cause further damage?

Continuing to drive with P1635 may lead to poor engine performance, potential stalling, and increased fuel consumption. It is recommended to address the issue promptly to prevent further damage.

6. Is it safe to clear the OBDII code P1635 Chevrolet with a diagnostic tool?

Clearing the code without addressing the underlying issue may temporarily turn off the Check Engine Light, but the problem will likely persist. It is crucial to diagnose and repair the root cause of P1635.

7. How can I repair the 5-volt reference circuit low condition (P1635) in my Chevrolet?

Repairing P1635 involves fixing any damaged wiring or connectors, replacing faulty sensors or components drawing excessive current, and reprogramming or replacing the PCM if necessary.

8. Will resetting the PCM fix the OBDII code P1635 Chevrolet?

Resetting the PCM may temporarily clear the code, but if the underlying issue causing P1635 is not addressed, the code is likely to return. Proper diagnosis and repair are essential for a lasting solution.

9. Can a DIY enthusiast fix the OBDII code P1635 Chevrolet at home?

Depending on their skill level and access to tools, a DIY enthusiast may be able to fix P1635 by following diagnostic procedures, checking wiring and connectors, and replacing faulty components. However, professional help may be required for complex repairs.

10. How much can I expect to pay to fix the OBDII code P1635 Chevrolet at a repair shop?

The cost of repairing P1635 can vary depending on the exact cause, parts needed, and labor rates. On average, the repair cost may range from $100 to $500 at a repair shop, but prices can be higher for more severe issues.