Powertrain, generic · Transmission

P07C8 Intermediate Shaft Speed Sensor B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

These low/high codes are a purely electrical check of the sensor's signal voltage at the module and run even with the vehicle at rest – unlike the circuit, range, no-signal and intermittent codes, which evaluate speed while driving. Low means a short to ground, high a short to supply or, depending on the circuit, an open. Intermediate shaft sensor B is a further sensor on a countershaft or planetary element. No manufacturer document available to us uses this code; GM reports further 10-speed intermediate sensors under its own codes. The expected logic follows the other sensors (above about 4.75 V); the speed-based codes for sensor B are P2745–P2748.

Likely causes

Signal wire shorted to supply
Open circuit or broken wire inside the sensor
Corroded connector
Module input faulty

Symptoms

  • Check engine light (GM after one trip)
  • Limp mode, harsh shifts, no converter lock-up
  • Adaption frozen

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€120–600
Time1–4 h

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

Parts involved

intermediate shaft speed sensorsensor wiringtransmission control module

Related codes

P07C7P2745P2746P2747P2748

References: law.cornell.edu, gsi.ext.gm.com, newtonnet.co.uk.