Pinpoint Test Al: P0C66

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Normal Operation and Fault Conditions

REFER to: Electric Powertrain Control - Component Location .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
SOBDMC P0C66:00	Generator Position Sensor Circuit "A" Low: No Sub Type Information	This DTC sets when a short to ground is detected in the generator resolver circuit.

Possible Sources

Wiring, terminals or connectors
Inverter System Controller (ISC) calibration

AL1 CHECK THE INVERTER SYSTEM CONTROLLER (ISC) CALIBRATION LEVEL

NOTE: Wiring overlays or repinning of circuits are NOT appropriate for DTC P0C66 due to risk of hardware damage.
- Verify the Inverter System Controller (ISC) is at the latest calibration level.
Is the Inverter System Controller (ISC) at the latest calibration level?

Yes GO to AL2

No UPDATE the Inverter System Controller (ISC) to the latest calibration level.

AL2 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) P0C66

Ignition ON.

Using a diagnostic scan tool, retrieve all Inverter System Controller (ISC) DTCs.

Was DTC P0C66 read from the Inverter System Controller (ISC)?

Yes

GO to AL3

No	The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

AL3 VISUAL INSPECTION OF THE LOW VOLTAGE SYSTEM
- Ignition OFF.
- Remove the high voltage traction battery service disconnect plug.
- Visually inspect all the low voltage cables.
- Make sure all the low voltage connectors are correctly and securely connected.
- Examine all the low voltage cables and connectors for damaged, burned or overheated insulation and loose or broken connections.
Is a concern present?

Yes REPAIR as necessary. CLEAR the DTCs and REPEAT the self-test.

No GO to AL4

AL4 CHECK THE GS3 CIRCUIT FOR A SHORT TO GROUND

Disconnect Transmission Sensor Speed Resolver C1280.

Disconnect Inverter System Controller (ISC) C1458A.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C1458A-B3	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10K ohms?

Yes

GO to AL5

No	REPLACE the harness. CLEAR the DTCs and REPEAT the self-test.

AL5 CHECK FOR CORRECT INVERTER SYSTEM CONTROLLER (ISC) OPERATION

Ignition OFF.

Inspect all Inverter System Controller (ISC) connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect all of the previously disconnected connectors. Make sure they seat and latch correctly.

Ignition ON.

Using a diagnostic scan tool, clear all Inverter System Controller (ISC) DTCs.

Using a diagnostic scan tool, retrieve all Inverter System Controller (ISC) DTCs.

Is DTC P0C66 present?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, REFER to: Powertrain Control Module (PCM) Input and Output Controls . Pinpoint Test Z.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.