AutoCodes – Cadillac – P15A0 Cadillac

P15A0 Cadillac Code - Fuel Economy Mode Switch Circuit High Voltage

Quick Answer

The Engine Control Module (ECM) supplies 5 V reference voltage, through the 5 V reference voltage circuit, to the S87 fuel economy mode switch. Common causes include Faulty Fuel Economy Mode Switch, Fuel Economy Mode Switch harness is open or shorted, Fuel Economy Mode Switch 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: P15A0 Cadillac indicates Fuel Economy Mode Switch Circuit High Voltage.
Common causes: Common causes include Faulty Fuel Economy Mode Switch, Fuel Economy Mode Switch harness is open or shorted, Fuel Economy Mode Switch 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 2,356

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 Jan 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P15A0 Cadillac Description

The Engine Control Module (ECM) supplies 5 V reference voltage, through the 5 V reference voltage circuit, to the S87 fuel economy mode switch. The 5 V reference voltage causes current to flow through a series of resistors in the switch to the switch ground circuit. The ECM monitors the reference voltage through a discrete fuel economy mode switch signal circuit. When the switch button is momentarily pressed, the switch contacts allow the 5 V reference voltage to by-pass one of the resistors. The ECM detects the resulting voltage drop as a fuel economy mode request and sends a GMLAN message to the Transmission Control Module (TCM) indicating the request. When the TCM receives the request, throttle progressions and transmission shift points are modified to optimize fuel efficiency. The Instrument Panel Cluster (IPC) also receives the fuel economy mode request message from the ECM and illuminates the fuel economy mode indicator lamp. The fuel economy mode switch must be pressed for between 0.094-1.5 s to activate the fuel economy mode.

OBDII Code P15A0 Cadillac - Fuel Economy Mode Switch Circuit High Voltage - AutoCodes.com — P15A0 Cadillac Code - Fuel Economy Mode Switch Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P15A0 Cadillac?

Faulty Fuel Economy Mode Switch
Fuel Economy Mode Switch harness is open or shorted
Fuel Economy Mode Switch circuit poor electrical connection

How to Fix the DTC P15A0 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 P15A0 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.

Need more information about the P15A0 Cadillac code?

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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 P15A0 Cadillac Code

1. What are the common symptoms of OBDII code P15A0 in a Cadillac related to the Fuel Economy Mode Switch Circuit High Voltage?

- Common symptoms include poor fuel economy, reduced engine performance, and the illumination of the Check Engine Light.

2. What can cause the Fuel Economy Mode Switch Circuit High Voltage issue in a Cadillac triggering code P15A0?

- Possible causes include a faulty fuel economy mode switch, damaged wiring or connectors in the circuit, or a malfunctioning engine control module (ECM).

3. How can I diagnose the Fuel Economy Mode Switch Circuit High Voltage problem in my Cadillac with OBDII code P15A0?

- Diagnosis typically involves checking the condition of the fuel economy mode switch, inspecting the circuit for any visible damage, and using a multimeter to test for voltage irregularities.

4. Are there any simple repair tips for addressing the P15A0 code related to the Fuel Economy Mode Switch Circuit High Voltage in a Cadillac?

- Start by ensuring the fuel economy mode switch is functioning properly and that all wiring connections are secure. If no visible issues are found, consider consulting a professional mechanic for further diagnosis and repair.

5. Can I continue driving my Cadillac with the P15A0 code indicating Fuel Economy Mode Switch Circuit High Voltage without immediate repairs?

- While the vehicle may still be operable, driving with this issue can lead to decreased fuel efficiency and potential long-term engine performance issues. It is recommended to address the problem promptly.

6. Is it possible to reset the Check Engine Light after repairing the Fuel Economy Mode Switch Circuit High Voltage problem causing OBDII code P15A0 in a Cadillac?

- Yes, the Check Engine Light can typically be reset using an OBDII scanner after the issue has been diagnosed and repaired. This will clear the code and monitor the system for any recurring problems.

7. How much does it cost to repair the Fuel Economy Mode Switch Circuit High Voltage issue triggering code P15A0 in a Cadillac?

- Repair costs can vary depending on the specific cause of the problem, the extent of the damage, and labor rates in your area. It's advisable to obtain quotes from reputable repair shops for an accurate estimate.

8. Can a DIY enthusiast with basic automotive knowledge fix the P15A0 code related to the Fuel Economy Mode Switch Circuit High Voltage in a Cadillac?

- While some individuals may be able to diagnose and repair simple issues like loose connections, more complex problems with the fuel economy mode switch or ECM may require professional expertise to ensure proper resolution.

9. How long does it typically take to repair the Fuel Economy Mode Switch Circuit High Voltage issue causing OBDII code P15A0 in a Cadillac?

- The repair time can vary depending on the exact cause of the problem and the extent of the repairs needed. Simple fixes may take a few hours, while more complex issues could require additional time for diagnosis and parts replacement.

10. Are there any preventative maintenance steps I can take to avoid the recurrence of the P15A0 code related to the Fuel Economy Mode Switch Circuit High Voltage in my Cadillac?

- Regularly inspecting and maintaining the fuel economy mode switch, checking wiring connections, and staying up to date on routine vehicle maintenance can help prevent issues that may trigger the P15A0 code.