AutoCodes – Cadillac – P1E21 Cadillac

P1E21 Cadillac Code - Auxiliary Transmission Fluid Pump Control Module Hybrid/EV Battery Voltage Sense Circuit High Voltage

Quick Answer

The power inverter module, often referred to as the drive motor generator power inverter module, contains three motor control modules and the hybrid powertrain control module. Common causes include Program Power Inverter Module, Faulty Power Inverter Module, Power Inverter Module 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: P1E21 Cadillac indicates Auxiliary Transmission Fluid Pump Control Module Hybrid/EV Battery Voltage Sense Circuit High Voltage.
Common causes: Common causes include Program Power Inverter Module, Faulty Power Inverter Module, Power Inverter Module 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 752

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Apr 23, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1E21 Cadillac Description

The power inverter module, often referred to as the drive motor generator power inverter module, contains three motor control modules and the hybrid powertrain control module. Two of the motor control modules operate their respective drive motor generator based upon power inverter module commands. The third motor control module controls the auxiliary transmission fluid pump motor. Each drive motor control module monitors its internal high voltage sensor for correct operation, no external circuits are involved. The motor control modules and the hybrid powertrain control module are part of the power inverter module and are not serviced separately.

OBDII Code P1E21 Cadillac - Auxiliary Transmission Fluid Pump Control Module Hybrid/EV Battery Voltage Sense Circuit High Voltage - AutoCodes.com — P1E21 Cadillac Code - Auxiliary Transmission Fluid Pump Control Module Hybrid/EV Battery Voltage Sense Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1E21 Cadillac?

Program Power Inverter Module
Faulty Power Inverter Module
Power Inverter Module harness is open or shorted
Power Inverter Module circuit poor electrical connection

How to Fix the DTC P1E21 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 P1E21 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 P1E21 Cadillac Code

What does the OBDII code P1E21 indicate for my Cadillac?

The P1E21 code indicates a problem with the Auxiliary Transmission Fluid Pump Control Module, specifically that the hybrid/EV battery voltage sense circuit is reading high voltage.

What are common symptoms associated with the P1E21 code?

Common symptoms may include the vehicle entering limp mode, reduced power during acceleration, unusual transmission behavior, or warning lights illuminated on the dashboard.

What might cause the P1E21 code to trigger?

Potential causes include a faulty auxiliary transmission fluid pump control module, damaged wiring or connectors in the voltage sense circuit, or issues with the hybrid/EV battery itself.

Can I drive my Cadillac if the P1E21 code is present?

It is generally not recommended to drive the vehicle when the P1E21 code is present, as it may lead to further transmission issues or a total loss of power.

How can I diagnose the P1E21 code accurately?

To diagnose the P1E21 code, use an OBDII scanner to check for additional codes, inspect wiring and connectors for damage, and test the auxiliary transmission fluid pump control module for proper function.

What repairs are typically needed to fix the P1E21 code?

Repairs may involve replacing the auxiliary transmission fluid pump control module, repairing any damaged wiring or connectors, or addressing issues with the hybrid/EV battery that may affect voltage readings.

Is it safe to ignore the P1E21 code?

Ignoring the P1E21 code could lead to more severe transmission problems and potential safety hazards, so it is advisable to address it promptly.

How can I reset the P1E21 code after repairs?

After completing the necessary repairs, you can reset the P1E21 code by using an OBDII scanner to clear the trouble codes, or by disconnecting the vehicle's battery for a few minutes.

What should I do if the P1E21 code returns after repairs?

If the P1E21 code returns, further diagnosis is needed. Check for any underlying issues that may not have been addressed, and consider consulting a professional mechanic for a more thorough inspection.