SPN 27
CAUTION
EGR valve position
The truck's control module (ECU) reports a fault on: EGR valve position.
SPN 27 means a truck control module (ECU) flagged a fault on EGR valve position, part of the EGR system on heavy-duty diesel trucks. DERATE rates it CAUTION: drive to a shop today, because the engine may cut power. Part usually replaced: EGR valve, $350–$1,400 (aftermarket to dealer) plus 2–4 h labor.
EGR
Can I keep driving?
Drive to a shop today. The engine may cut power (derate) if the fault stays active.
Most likely causes
Sooted EGR valve
Position sensor circuit
Recommended tests
1. Command EGR valve and watch position feedback
Part usually replaced
EGR valve
$350–$1,400 (aftermarket to dealer)
Labor: 2–4 h
USD, part only. Labor is billed at the shop's hourly rate.
Data: DERATE verified base, updated October 2026
Related codes
Read it off your own dash
Take one photo and DERATE tells you whether you can keep driving.
Ask DERATE
DERATE assists. It does not replace inspection by a qualified technician.