Powertrain, generic (extended)

P2600 Coolant Pump A Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2600 means the controller sees an open circuit on the line that drives electric coolant pump A, directly or through its relay. GM's 2023 ECM table tests the auxiliary coolant pump relay output while it is off: more than 200 kOhm for 5 of 6 seconds sets the code as Type B, so the MIL follows after two trips. On Ford's 2020-2023 gasoline engines pump A serves the cabin heating loop. Hyundai traces P2600 on 2016-2019 Sonata Hybrid and Plug-in Hybrid to an internal open or short in the electric engine water pump or to low coolant; Kia found water seeping into the housing of the auxiliary pump on early 2019 Niro hybrids, and Audi chafed gearbox wiring on 2023 A6/S6. P2602 and P2603 are the low and high faults, P2601 the function check.

Likely causes

Internal open circuit in the electric pump or its electronics
Water or coolant ingress causing poor contact at the pump
Chafed or broken control wire, loose connector or failed relay
Coolant level too low (named by Hyundai as possible trigger)

Symptoms

  • MIL or hybrid warning lamp on
  • Little or no cabin heat
  • Rising coolant temperature in hybrid or after-run operation

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–700
Time0.5–3 h

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

Parts involved

coolant pump apump relaywiring harness

Related codes

P2601P2602P2603P261A

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.