EGR Coolant Flow Fault
EGR cooling system isn't working as it should.
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 EGR cooler should cool down the exhaust gases before recirculating them, but it’s either leaking or clogged, causing overheating or poor engine performance.
What the computer is actually seeing
The Engine Control Module (ECM) monitors the EGR system temps and flow; if it sees a consistent difference from expected values, it triggers the code.
What a healthy reading looks like
The EGR coolant inlet/outlet temperatures should differ roughly by 20-30°F when operating normally; flow rate should be steady under EGR operation.
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 EGR cooler for visible leaks or damage.
- 22. Inspect the EGR valve operation; it should open and close freely while the engine is running.
- 33. Measure the coolant flow to the EGR cooler; it should be steady, without significant drop.
- 44. Verify coolant temperature differences at inlet and outlet; if no difference or excess, there's an issue. Confirm sensor readings are accurate.
- 55. If all checks are good, replace the EGR cooler.
Common causes
- Clogged EGR cooler
- Leaking EGR cooler
- Failed EGR valve
- Faulty coolant temperature sensors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but perform the fix soon to avoid engine overheating.
Will the code come back after repairs?
Not if the repair was done properly.
Why does this code pair with SPN 2771?
SPN 2771 indicates EGR valve faults, often linked with cooling issues.
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