Powertrain, generic (extended)

P24A7 EGR Cooler Coolant Pump Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Some diesel engines feed the EGR cooler with an electric auxiliary coolant pump so the cooler gets flow at low engine speed or after shut-off, independent of the main pump. P24A7 means the engine controller sees an open or otherwise faulty control line to this pump, typically when the driver stage detects no load while switching. No manufacturer documents this code publicly with thresholds, and no NHTSA bulletin index entry names it; the text relies on CARB's comprehensive component rules for outputs and on supplier information on EGR coolers in the coolant circuit. Check connector, wiring and pump fuse first. P24A9 and P24AA split the same circuit into shorts to ground and to supply. Without flow the cooler can overheat, so EGR may be reduced.

Likely causes

Loose, corroded or unplugged pump connector
Broken control wire in the harness
Open winding or electronics in the pump

Symptoms

  • Malfunction indicator lamp on
  • EGR may be reduced, NOx output rises

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egr cooler coolant pump

Related codes

P24A9P24AAP24A8P24AB

References: law.cornell.edu, ms-motorservice.com.