The P20C0: Reductant Heater ‘B’ Control Circuit High refers to an issue where the control circuit for reductant heater ‘B’ is experiencing higher-than-expected voltage. This could be due to problems with the heater, control module, or an electrical fault causing excessive voltage in the circuit.
P20C0 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P20C0: Reductant Heater ‘B’ Control Circuit High |
| Is it serious? | Yes, this issue can cause reductant heater ‘B’ to malfunction, potentially affecting emissions control. |
| Possible causes | – High voltage in the reductant heater ‘B’ control circuit – Faulty heater – Faulty control module |
| How to diagnose? | – Measure voltage in the heater control circuit – Test reductant heater ‘B’ – Check the control module functionality |
P20C0 Meaning
The P20C0 fault code signals that the control circuit for reductant heater ‘B’ is experiencing a high voltage condition. This could prevent the heater from functioning correctly, leading to improper emissions management. The issue could result from wiring faults, a malfunctioning heater, or a defective control module.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to look for related codes that might help further diagnose the issue. | OBD-II Scanner |
| Measure Voltage in the Heater Control Circuit | Measure the voltage in the control circuit for reductant heater ‘B’ using a multimeter. Ensure it is within the manufacturer’s specified range. | Multimeter |
| Test Reductant Heater ‘B’ | Use a diagnostic tool to test the functionality of reductant heater ‘B’ and check if it is drawing excessive power. | Multimeter, Diagnostic Tool |
| Inspect the Control Module | Test the control module to confirm that it is working properly and not causing the high voltage condition. | Diagnostic Tool |
| Repair or Replace Wiring/Heater | If high voltage is detected, inspect the wiring for faults and repair or replace reductant heater ‘B’ as needed. | Wiring Kit, Replacement Heater |
| Clear the Code and Test Drive | After performing repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to confirm the issue is resolved. | OBD-II Scanner, Vehicle Manual |
| Recheck for Codes | After the test drive, rescan the vehicle to ensure the P20C0 code does not return. | OBD-II Scanner |
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