For 1990-2009 cars only
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 P1A70: Starter/Generator Control Module System Voltage PerformanceCircuit/System Description
The starter/generator control module (SGCM) monitors the performance to detect 12-volt DC wire electrical failure by comparing the 12-volt input to the 12-volt output values. If the difference is greater than 5 volts, the DTC sets.
Conditions for Running the DTC
| • | The engine is running. |
| • | Hybrid mode is active. |
Conditions for Setting the DTC
The 12-volt power supply -- 12-volt output voltage is greater than 5 volts for 119 ms and any fault during 15 seconds wait period.
Action Taken When the DTC Sets
| • | Stop PWM (MGU shutdown). |
| • | APM PWM off. |
Conditions for Clearing the DTC
Cycle wake up signal.
Diagnostic Aids
Possible 12-volt battery or APM voltage sensor stuck.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Starter/Generator Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- With a scan tool, clear the DTC.
- Ignition OFF, wait 30 seconds.
- Ignition ON, operate the vehicle within the Conditions for Running the DTC and verify the DTC does not reset.
| ⇒ | If the DTC resets, replace the SGCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for SGCM replacement, setup, and programming
