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P220A Cadillac Code - NOx Sensor 1 Supply Voltage Circuit

Quick Answer

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. Common causes include Faulty Nitrogen Oxides (NOx) Sensor 1, Nitrogen Oxides Sensor 1 harness is open or shorted, Nitrogen Oxides Sensor 1 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: P220A Cadillac indicates NOx Sensor 1 Supply Voltage Circuit.
Common causes: Common causes include Faulty Nitrogen Oxides (NOx) Sensor 1, Nitrogen Oxides Sensor 1 harness is open or shorted, Nitrogen Oxides Sensor 1 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 311

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 Jul 27, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P220A Cadillac Description

The Nitrogen Oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. There are two NOx sensors, one placed upstream of selective catalytic reduction, to measure inlet NOx concentration, and one placed downstream. They are connected with the control module via CAN and all the information is exchanged through it. Since it is a smart sensor, all the electrical monitoring is performed inside the sensor and only the results are sent to the Engine Control Module (ECM). Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within the sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust. The ECM varies the amount of diesel exhaust fluid (reductant) added by varying the reductant injector duty cycle in response to changes in engine exhaust NOx levels. The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module. The Diagnostic Trouble Code (DTC) will be set when the sensor supply voltage is less than 10.8 V.

OBDII Code P220A Cadillac - NOx Sensor 1 Supply Voltage Circuit - AutoCodes.com — P220A Cadillac Code - NOx Sensor 1 Supply Voltage Circuit

What does this mean?

What are the Possible Causes of the DTC P220A Cadillac?

Faulty Nitrogen Oxides (NOx) Sensor 1
Nitrogen Oxides Sensor 1 harness is open or shorted
Nitrogen Oxides Sensor 1 circuit poor electrical connection

How to Fix the DTC P220A 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 P220A 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 P220A Cadillac Code

1. What are the common symptoms of a P220A OBDII code related to the NOx Sensor 1 Supply Voltage Circuit in a Cadillac?

- Common symptoms include poor engine performance, decreased fuel efficiency, rough idling, and potential issues with the vehicle's emissions.

2. What are the possible causes of the P220A OBDII code in a Cadillac's NOx Sensor 1 Supply Voltage Circuit?

- Possible causes include a faulty NOx sensor, damaged wiring or connectors, a defective powertrain control module (PCM), or issues with the vehicle's electrical system.

3. How can I diagnose the P220A OBDII code related to the NOx Sensor 1 Supply Voltage Circuit in my Cadillac?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code, inspecting the sensor and its wiring for damage, and testing the sensor's voltage and resistance.

4. Can I continue to drive my Cadillac with a P220A OBDII code related to the NOx Sensor 1 Supply Voltage Circuit?

- It is not recommended to drive the vehicle with this code present, as it can lead to further damage to the engine and emissions system. It is best to address the issue promptly.

5. How can I repair a P220A OBDII code in my Cadillac's NOx Sensor 1 Supply Voltage Circuit?

- Repair options may include replacing the NOx sensor, repairing or replacing damaged wiring or connectors, resetting the fault code with a scanner, or seeking professional assistance.

6. Are there any DIY tips for troubleshooting a P220A OBDII code in a Cadillac related to the NOx Sensor 1 Supply Voltage Circuit?

- DIY tips include checking for visible damage to the sensor and its wiring, ensuring proper connections, and resetting the code to see if it reoccurs after driving.

7. Is it necessary to reset the PCM after repairing a P220A OBDII code in a Cadillac's NOx Sensor 1 Supply Voltage Circuit?

- Yes, it is recommended to reset the PCM after completing any repairs related to the NOx sensor circuit to ensure the system recognizes the changes and clears the fault code.

8. Can extreme weather conditions affect the NOx Sensor 1 Supply Voltage Circuit and trigger a P220A OBDII code in a Cadillac?

- Extreme weather conditions can potentially impact the sensor's performance, wiring connections, and overall system functionality, leading to the activation of the fault code.

9. How often should the NOx sensor be inspected or replaced to prevent the recurrence of a P220A OBDII code in a Cadillac?

- It is advisable to follow the manufacturer's recommended maintenance schedule for inspecting and replacing the NOx sensor to prevent issues like the P220A code from reoccurring.

10. Will a P220A OBDII code related to the NOx Sensor 1 Supply Voltage Circuit cause my Cadillac to fail an emissions test?

- Yes, a P220A fault code indicates an issue with the emissions system, which can lead to a failed emissions test. It is essential to address the problem to ensure compliance and proper vehicle operation.