GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Hybrid 🢒 Hybrid Controls 🢒 DTC P1AFC, P1AFD, or P1B02

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P1AFC: Drive Motor 1 Control Module Serial Peripheral Interface (SPI) Bus

DTC P1AFD: Drive Motor 1 Control Module Serial Communications Interface (SCI) Bus

DTC P1B02: Drive Motor 2 Control Module Serial Peripheral Interface (SPI) Bus

Circuit/System Description

This is an internal fault detection of the drive motor generator power inverter module (PIM) assembly. This fault is handled inside the PIM and no external circuits are involved. The PIM contains two motor control modules (MCMs) and the hybrid powertrain control module (HPCM). In addition to GM LAN, these modules share dedicated, internal PIM communications circuits.

Conditions for Running the DTC
    • The control module runs the program to detect an internal fault when the key is ON.
    • Ignition voltage is 8-18 volts.

Conditions for Setting the DTC

P1AFC

MCM 1 detects a loss of SPI bus communication with the HPCM.

P1AFD

MCM 1 detects a loss of SCI bus communication with MCM 2 for 2 seconds.

P1B02

MCM 2 detects a loss of SPI bus communication with the HPCM.

Action Taken When the DTC Sets
    • DTCs P1AFC and P1B02 are Type A DTCs.
    • DTC P1AFD is a Type B DTC.
    • The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC
    • DTCs P1AFC and P1B02 are Type A DTCs.
    • DTC P1AFD is a Type B DTC.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification
  1. Clear the DTC information.
  2. Turn the ignition OFF for 1 minute.
  3. Turn the ignition ON.
  4. Retest for DTCs P1AFC, P1AFD and P1B02.

Circuit/System Testing

Ignition ON, retest for DTCs P1AFC, P1AFD and P1B02.

⇒If the DTC resets, program the PIM with the latest software version and recheck for DTCs. If the DTC resets after programming or if the PIM already contains the latest software version, replace the PIM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PIM replacement, setup, and programming.