P20C1 GMC Code - Reductant Heater 'C' Control Circuit/Open
Quick Answer
The reductant heater and sender assembly contains pickup tube for reductant pump module, an electric heating element, a reductant temperature sensor and an electrode type level sensor. Common causes include Faulty Reductant Heater, Reductant Heater harness is open or shorted, Reductant Heater 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
- P20C1 GMC indicates Reductant Heater 'C' Control Circuit/Open.
- Common causes
- Common causes include Faulty Reductant Heater, Reductant Heater harness is open or shorted, Reductant Heater 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.
Code P20C1 GMC Description
What are the Possible Causes of the DTC P20C1 GMC?
- Faulty Reductant Heater
- Reductant Heater harness is open or shorted
- Reductant Heater circuit poor electrical connection
How to Fix the DTC P20C1 GMC?
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 P20C1 GMC 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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Frequently Asked Questions about P20C1 GMC Code
What does the OBDII code P20C1 mean on a GMC vehicle?
The P20C1 code indicates an issue with the Reductant Heater 'C' Control Circuit, such as an open circuit or malfunction.
What are the common symptoms of code P20C1?
Symptoms may include the check engine light turning on, DEF system warnings, reduced engine power, or issues with cold-weather DEF operation.
What causes the P20C1 code to appear?
Possible causes include a faulty reductant heater, damaged wiring, corroded connectors, or a failed reductant heater control module.
Can I drive my GMC with the P20C1 code active?
Driving with this code is possible but not recommended, as it can lead to reduced DEF system efficiency and eventually trigger limp mode.
How do I diagnose the P20C1 code?
Start by inspecting the reductant heater wiring and connectors for damage or corrosion, then test the heater's resistance and check the control circuit for continuity.
What tools are needed to fix the P20C1 code?
Common tools include a diagnostic scanner, multimeter, wiring diagram, and possibly replacement parts like the reductant heater or related wiring.
How do I fix the P20C1 code on my GMC?
Repairs may involve replacing the reductant heater, repairing damaged wiring, cleaning corroded connectors, or replacing the control module if necessary.
What is the function of the reductant heater in a GMC vehicle?
The reductant heater prevents the diesel exhaust fluid (DEF) from freezing in cold weather, ensuring proper DEF flow and emissions system operation.
How much does it cost to repair the P20C1 code?
The cost depends on the specific issue but can range from $100 for minor wiring repairs to $500 or more for heater or module replacement.
Does the P20C1 code require reprogramming after repairs?
In some cases, the control module may need to be reset or updated using a diagnostic scanner after completing the repairs.
Discuss the causes and fixes for P20C1 GMC OBDII Code
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