AutoCodes – Cadillac – P1B18 Cadillac

P1B18 Cadillac Code - Hybrid/Electric Vehicle Battery 27 Circuit High Voltage

Quick Answer

The Hybrid/Electric Vehicle battery pack contains 288 cells. Common causes include Faulty Hybrid/Electric Vehicle Battery Pack, Faulty Hybrid/Electric Vehicle Battery Interface Control Module. 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: P1B18 Cadillac indicates Hybrid/Electric Vehicle Battery 27 Circuit High Voltage.
Common causes: Common causes include Faulty Hybrid/Electric Vehicle Battery Pack, Faulty Hybrid/Electric Vehicle Battery Interface Control Module.
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 733

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 Mar 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B18 Cadillac Description

The Hybrid/Electric Vehicle battery pack contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack assembly. These cell groups are electrically connected in-series. Each individual cell group is rated at 3.7 V, for a nominal system voltage of 355 V direct current. The battery cells are also grouped together into three sections. The first 90 cells/30 cell groups make up battery section one. This section is adjacent to the cowl and contains batteries 67 through to 96. Battery section two is located behind section one. It is made up of 72 cells/24 cell groups and contains batteries 43 through to 66. The transverse battery section is section number three, it is made up of the remaining 126 cells/42 cell groups and contains batteries 1 through to 42. The three battery sections are individually serviceable components.
The battery energy control module monitors the voltage of the 96 battery cell groups through the four hybrid/EV battery interface control modules. Voltage sense circuits are attached to each individual cell group, and these sense circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness joins this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module through the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.
The battery energy control module will determine when a fault condition is present. Diagnostics and system status are communicated from the battery energy control module to hybrid/EV powertrain control module 2 through serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

OBDII Code P1B18 Cadillac - Hybrid/Electric Vehicle Battery 27 Circuit High Voltage - AutoCodes.com — P1B18 Cadillac Code - Hybrid/Electric Vehicle Battery 27 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1B18 Cadillac?

Faulty Hybrid/Electric Vehicle Battery Pack
Faulty Hybrid/Electric Vehicle Battery Interface Control Module

How to Fix the DTC P1B18 Cadillac?

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 P1B18 Cadillac 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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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 P1B18 Cadillac Code

1. What are common symptoms of OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle?

- Common symptoms include the hybrid/electric vehicle not starting or charging properly, reduced fuel efficiency, warning lights on the dashboard, and potential loss of power.

2. What could be causing the OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle?

- The code P1B18 indicates a high voltage issue in the battery 27 circuit, which could be caused by a faulty battery pack, damaged wiring, poor connections, or a malfunctioning battery management system.

3. How can I diagnose the OBDII code P1B18 in my Cadillac Hybrid/Electric Vehicle?

- Diagnosing the code typically involves using a diagnostic scanner to retrieve the specific fault codes, inspecting the battery pack and related components for any physical damage, testing the voltage levels in the circuit, and checking for loose or corroded connections.

4. What are the potential risks of driving with the OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle?

- Driving with the code P1B18 can lead to further damage to the high voltage circuit, potential safety hazards due to high voltage exposure, and may cause the vehicle to enter a reduced power mode or fail to operate altogether.

5. How can I repair the OBDII code P1B18 in my Cadillac Hybrid/Electric Vehicle?

- Repairing the code P1B18 may involve replacing the faulty battery pack, repairing damaged wiring or connections, resetting the battery management system, and clearing the fault codes with a diagnostic tool.

6. Is it safe to attempt DIY repairs for the OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle?

- Due to the high voltage nature of the system, it is recommended to have repairs related to the code P1B18 performed by trained professionals or technicians with experience working on hybrid/electric vehicles to avoid potential safety risks.

7. How much does it typically cost to repair the OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle?

- The cost of repairing the code P1B18 can vary depending on the extent of the damage, parts needed for replacement, labor costs, and whether the repair is done at a dealership or an independent repair shop. Costs can range from a few hundred to a few thousand dollars.

8. Can the OBDII code P1B18 in a Cadillac Hybrid/Electric Vehicle be prevented?

- Regular maintenance, timely inspections of the high voltage system, keeping the battery pack in good condition, and addressing any warning signs promptly can help prevent the occurrence of the code P1B18 in a Cadillac Hybrid/Electric Vehicle.