Diagnostic Instructions
DTC Descriptor
DTC P1A8F: 14 Volt Power Module Current Sensor Overcurrent
Circuit/System Description
The starter/generator control module (SGCM) monitors the 14-volt power module current sensor for an overcurrent condition to protect the MOSFET. In the hardware an overcurrent protection circuit is used to limit the current, and software monitors for an
overcurrent reading in the sensor.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
The 12-volt charge is greater than 150 amps or less than -150 amps for 2 seconds
Action Taken When the DTC Sets
- | Stop PWM (MGU shutdown) |
- | Stop PWM (MGU shutdown) |
- | Battery disconnection (disconnect SW on/off) |
Hybrid system is disabled.
Conditions for Clearing the DTC
• | In the software fault, APM current less than +/- 10 amps |
• | 12VOUT is greater than 7 volts. |
• | APMTEMP is less than 105°C (221°F) for 160 ms. |
• | Clears 30 seconds after cycle wake up signal. |
Diagnostic Aids
• | Battery cable short to ground |
• | Fuse/relay box electrical failures |
Reference Information
Schematic Reference
Hybrid Controls Schematics
Connector End View Reference
Hybrid Controls Connector End Views
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Verification
Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both
engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using
a DMM before proceeding.
- Inspect for any open fuses.
- Inspect all the 12-volt battery connections for short to ground as follows:
- If all connections are normal, replace the SGCM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Control Module References
for SGCM replacement, setup, and programming