Reductant Pump Performance
The reductant pump is not performing as expected.
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 truck's system that injects diesel exhaust fluid (DEF) isn't working right, which means it can't effectively reduce the pollution levels coming out of the exhaust.
What the computer is actually seeing
The engine control module (ECM) monitors the performance of the reductant pump. If it detects that the pump's output pressure or flow rate falls outside the expected range, it triggers the code P202D.
What a healthy reading looks like
The pump should achieve a flow rate of at least 12 mL/min and maintain pressure between 10-15 PSI when activated.
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 DEF fluid level; it should be above the minimum mark and free of contaminants.
- 22. Inspect the wiring and connectors to the reductant pump for any signs of damage or corrosion; repair as necessary.
- 33. Use a scan tool to monitor pump operation; observe the flow rate and pressure while the engine is running.
- 44. If unable to achieve expected flow rate of 12 mL/min, replace the reductant pump and recheck.
- 55. Erase the code and test drive the vehicle; check for recurrence of the P202D code.
Common causes
- Faulty reductant pump
- Blocked DEF lines
- Electrical issues (wiring/connectors)
- Low DEF fluid level or contamination
- Failed ECM with incorrect parameter calculations
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
You can drive, but emissions may be higher and exhaust systems may not work correctly, which could lead to future issues.
Will this code come back after clearing it?
If the underlying issue isn't resolved, the code will reappear after a short period of driving.
Why does this code sometimes appear with other codes?
P202D is often triggered alongside other reductant system codes when there's an overall failure in the DEF system.
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