Powertrain, generic · Auxiliary emission controls

P045A EGR B Control Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. EGR B is a second EGR valve next to valve A – on diesels with two EGR circuits the low-pressure valve, which takes exhaust after the particulate filter and feeds it in before the turbo compressor. GM's diesels of 2016–18 and FCA's 2.2-litre diesel in the Jeep Wrangler use it. P045A is the general electrical fault in the drive circuit of valve B, typically an open circuit (for valve A GM uses 200 kΩ or more). GM lists this code among those that switch off the low-pressure EGR position control, but publishes no thresholds for it; the description follows the comparable valve A checks and CARB, which requires output circuits to be monitored. Low-pressure EGR is then switched off.

Likely causes

Connector at EGR valve B corroded or loose
Harness chafed or heat-damaged
Actuator motor in valve B open
Driver in the engine module

Symptoms

  • Check engine light on
  • Low-pressure EGR switched off, possibly higher NOx
  • Usually no change in driving

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time0.5–3 h

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

Parts involved

egr valve blow pressure egr valveegr wiringengine control module

Related codes

P045CP045DP045BP0403P044CP049E

References: gsi.ext.gm.com, law.cornell.edu, patents.google.com, static.nhtsa.gov.