Powertrain, generic (extended)

P2699 Exhaust Aftertreatment Fuel Injector A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2699 flags the drive circuit of the exhaust fuel doser as too low, usually a grounded control wire or a shorted valve coil. The difference to P2697 matters in practice: an open circuit simply stops dosing, while a grounded line can switch the valve on without command if the short sits behind the driver, so raw fuel may reach a cold catalyst. Volvo and Mack list P2699 with failure type 00 among the electrical faults of their aftertreatment hydrocarbon injector system and send the technician to the dosing module plug and harness, in the same guide that covers the open and high cases. No other maker documents the code publicly. Expect a lit MIL, cancelled regenerations and, if dosing stays blocked, a rising filter load with eventual power reduction.

Likely causes

Doser control wire grounded against the frame or exhaust bracket
Shorted coil of the dosing valve
Fuel or water inside the module connector

Symptoms

  • MIL on and regeneration inhibited
  • Possible white smoke if the valve opens uncommanded
  • Derate after prolonged soot build-up

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–1,500
Time0.5–3 h

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

Parts involved

hc dosing injectorinjector solenoidwiring harness

Related codes

P2697P2698P269A

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.