Reductant Pump A Control Circuit/Open
This code indicates a fault in the reductant pump's control circuit or an open circuit condition.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer is trying to use the reductant pump to inject diesel exhaust fluid (DEF) for emissions control, but it can't communicate with the pump, meaning the fluid won't be injected as needed.
What the computer is actually seeing
The engine control module (ECM) sees no voltage or a fault in the signal line for the reductant pump, which should normally be around 12-14 volts when activated.
What a healthy reading looks like
When the pump is commanded, the voltage at the pump connector should be between 12-14 volts. During operational state, the current draw should be around 1-5 amps depending on the DEF flow rate.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the fuse for the reductant pump circuit. If blown, replace it and see if the code returns.
- 22. Inspect the wiring and connectors to the reductant pump. Look for damage, corrosion, or loose connections. Repair as necessary.
- 33. Use a multimeter to check for voltage at the pump connector while the engine is running. You should see 12-14 volts when the pump is commanded on. If not, the issue is upstream.
- 44. If voltage is present but the pump is not operating, remove the pump and test it directly with a 12V battery. If it does not run, replace the pump.
- 55. Clear the code and test drive the vehicle to see if the code returns.
Common causes
- Open circuit in the wiring harness to the reductant pump
- Faulty reductant pump
- Bad connector at the pump or ECM
- Blown fuse for reductant pump circuit
- Water or contamination in the pump or harness
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's advisable to get this fixed soon since it impacts emissions and can lead to reduced power or limp mode.
How long before the code comes back after clearing?
If the issue isn't resolved, the code may return immediately or after a short drive cycle.
Why does this code appear with other codes?
It's common for related issues in emissions systems to trigger multiple fault codes.
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