P0C59: Drive Motor B Position Sensor Circuit A Intermittent/Erratic

P0C59 reports that Circuit A of the motor B resolver drops out or jumps for moments only, without a fault that persists as low, high or implausible. No manufacturer documents this code publicly. Where a dual-motor system uses it, the cause is nearly always mechanical: a terminal that loses grip under vibration, a cable section that flexes with the transmission, or water creeping into a plug. The GM truck note PIP4607A shows how a single poorly crimped terminal at the transmission pass-through connector can upset resolver signals of motor B. Since short glitches on a position signal disturb torque control, the controller may still cut motor B briefly. P0C57 and P0C58 are the steady faults on the same winding.

Symptoms

• Warning lamp that comes and goes
• Short loss of motor B assistance or a jerk
• Intermittent start problems on some hybrids

Most likely causes

• Poorly crimped or loose terminal in the motor B Circuit A path
• Wire breaking inside its insulation where the harness flexes
• Water ingress at the resolver or pass-through connector

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• Repair difficulty: hard
• It can trigger limp mode.
• It affects emissions.

What each character of P0C59 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• C: Subsystem depends on the code range
• 59: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0C59?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0C59?

The most common causes are: poorly crimped or loose terminal in the motor B Circuit A path; wire breaking inside its insulation where the harness flexes; water ingress at the resolver or pass-through connector.

Related codes

• P0C55Drive Motor B Position Sensor Circuit A
• P0C57Drive Motor B Position Sensor Circuit A Low
• P0C58Drive Motor B Position Sensor Circuit A High
• P0C63Drive Motor B Position Sensor Circuit B Intermittent/Erratic
• P0A49Drive Motor B Position Sensor Circuit Intermittent

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 10154556 9999
• en.wikipedia.org: Resolver (electrical)

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.