Circuit 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, APO Continuous). The APO switch is a momentary button, its output signal an input to an HCM analogue channel. Five volts are supplied to the switch and 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.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B3654 Electrical Power Take Off Control Switch Circuit |
| • | DTC B3655 Electrical Power Take Off Control Switch Circuit Low |
| • | DTC B3656 Electrical Power Take Off Control Switch Circuit High |
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The APO switch is requested ON. |
Conditions for Setting the DTC
| • | If voltage is lower than a calibrated value , a short low is indicated. |
| • | If the voltage is greater than a calibrated value the short high is indicated. |
| • | This DTC is run every 100 ms. |
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
Conditions for Clearing the DTC
| • | The Conditions for Setting the DTC are no longer present. |
| • | A history DTC will clear after 40 malfunction-free ignition cycles. |
| • | The HCM receives the clear code command from the scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Cigar Lighter/Power Outlet Schematics Connector End View Reference: Power Outlet Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the scan tool display ON? | Go to Step 3 | Go to Step 4 |
3 |
Does the APO Switch Status parameter display OFF? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
4 |
Does the scan tool display OFF? | Go to Step 7 | Go to Step 5 |
5 | Test the signal circuit of the APO switch for a open or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 6 |
6 | Inspect for poor connections at the harness connector of the HCM . Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the APO switch. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
8 | Replace the HCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 10 | -- |
9 | Replace the APO switch. Refer to Accessory Switch Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 |
Does the DTC reset? | Go to Step 2 | System OK |
