P21C7
Reductant Control Module Power Relay/Relays Control Circuit/Open
P21C7 is an OBD-II diagnostic trouble code meaning: Reductant Control Module Power Relay/Relays Control Circuit/Open. Common causes: open circuit in the relay control circuit, faulty regenerator module relay. Estimated repair cost: $17–89.
Symptoms
- Check Engine Light Is On
- Reduced engine power
- Increased fuel consumption
- Possible transition to emergency mode
- Increased NOx emissions
Causes
- Open circuit in the relay control circuit
- Faulty regenerator module relay
- Wiring Harness Problems
- Reducer module malfunction
- Short circuit in the circuit
How to Fix
- Check the integrity of the relay control circuit
- Check relay functionality
- Inspect the wiring harness for damage
- Check the power supply and ground of the reducing agent module
- If necessary, replace the relay or restorer module
Related codes
Error P21C7 by Vehicle Brand
FAQ
What does the P21C7 code mean?
P21C7 is an OBD-II diagnostic trouble code that indicates: Reductant Control Module Power Relay/Relays Control Circuit/Open
What causes a P21C7 error code?
The most common causes of P21C7 include: Open circuit in the relay control circuit; Faulty regenerator module relay; Wiring Harness Problems; Reducer module malfunction.
How do I fix a P21C7 diagnostic trouble code?
To fix P21C7: Check the integrity of the relay control circuit. Check relay functionality. Inspect the wiring harness for damage. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21C7?
Yes, but get it checked soon
How much does it cost to fix P21C7?
The estimated repair cost for P21C7 is $17–89. Actual cost depends on your vehicle, location, and labor rates.
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