Powertrain, generic · Transmission

P097B Shift Solenoid B Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Open-circuit fault in the drive circuit of shift solenoid B. Public use is again limited to GM's Allison 1000 six-speed in heavy-duty trucks, where the 2022 to 2025 tables label it Shift Solenoid 2 Control Circuit Open. SS2 shares high-side driver 2 with SS1 and SS3, so the open test only runs while that supply is on and free of P2669, P2670 or P2671. It confirms an open by switching the low-side driver off and needs three samples, 120 ms, MIL after one trip. Allison's 2007 table filed the same check as P0975, the 2016 table under P0976. Ford reports an open SSB as P0755, GM six-speeds as P0977. Low/high are P0976/P0977.

Likely causes

Open coil of shift solenoid 2/B
Loose or corroded terminal on the solenoid B circuit
Wire broken by vibration or heat near the transmission
Faulty driver stage in the control module

Symptoms

  • MIL on after one faulty trip
  • Default gear operation, some ranges unavailable
  • Harsh or missing shifts

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time1–5 h

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

Parts involved

shift solenoid bwiring harnesstcm

Related codes

P0975P0976P0977P0755P097AP097C

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.