DTC Descriptor
DTC B1422: Device Power Moding Error
Diagnostic Fault Information
Perform the
Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
The auxiliary power outlet (APO) switch controls the operation of the hybrid control module (HCM) APO state manager. The APO state manager commands one of 3 states from the starter generator control module (SGCM): APO Off, APO Normal, and APO Continuous.
The APO switch is a momentary button, its output signal is an input to an HCM analog channel. Five volts are supplied to the switch. The returned voltage is measured relative to HCM signal ground to determine the switch state. A resistor network in the switch
circuitry ensures that shorted high and low states can be diagnosed successfully. There are 2 valid voltage ranges of the return signal, one representing switch open, the other representing switch closed. If the voltage is lower than a threshold, a short
low is indicated. Similarly, if the voltage is greater than the short high threshold, a short high is indicated.
The SGCM uses the interlock circuit to monitor the plugs and connectors for hybrid system function. The interlock indicates the state of the connectors in the 120 voltage circuits. In the SGCM, the primary side of the transformer is connected to
a low frequency oscillator circuit. When the loop is complete, the shorted secondary reduces the oscillator voltage, and a comparator senses this as a good and complete interlock loop. If the loop is open, the oscillator amplitude increases and the comparator
senses this as a problem.
Conditions for Running the DTC
The engine is ON.
Conditions for Setting the DTC
| • | The HCM senses a low or no voltage condition at the power maintain relay coil control circuit. |
| • | This diagnostic runs continuously. |
Action Taken When the DTC Sets
| • | The Auxiliary Power Outlets (APO) are disabled. |
| • | The HCM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The APO switch LED does not illuminate. |
Conditions for Clearing the DTC
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
| • | Use the scan tool in order to clear the DTC. |
Reference Information
Schematic Reference
Cigar Lighter/Power Outlet Schematics
Connector End View Reference
Power Outlet Connector End Views
Electrical Information Reference
Circuit/System Testing
- Ignition OFF, disconnect the Power Maintain Relay.
- Ignition ON, verify that a test lamp illuminates between the control circuit terminal A2 and ground.
| ⇒ | If the test lamp does not illuminate, test the control circuit for an open/high resistance. |
- Verify that a test lamp illuminates between the control circuit terminal A2 and C1.
| ⇒ | If the test lamp does not illuminate, test for an open/high resistance between the control circuit terminal C1 and the hybrid control module (HCM) terminal 49. If the circuit tests normal, test or replace the HCM. |
- Ignition OFF, disconnect the harness connector of the HCM. Verify that a test lamp does not illuminate between the control circuit terminal C1 and ground.
| ⇒ | If the test lamp illuminates, test the circuit for a short to ground. |
- If all circuits test normal, replace the Power Maintain Relay.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for HCM replacement, setup, and programming.
