P1215
CIRCUIT DESCRIPTIONThe Alternative Fuels ECM contains electronic devices called output driver modules. The output driver modules provide switchable outputs (control circuits) for operating solenoids, relays, telltales, and other devices. Each of the outputs has an internal fault line that the Alternative Fuels ECM can monitor for faulted circuit conditions.
Two types of outputs can be utilized. High side drivers supply voltage on the control circuit. Low side drivers supply a ground on the control circuit. Currently all monitored outputs are low side drivers. In order for the fault line to detect a failure, the state of the control circuit must be opposite of the expected state. If the Alternative Fuels ECM is commanding an output ON, then 0 volts should be monitored by the fault line. If the Alternative Fuels ECM is commanding an output OFF then the voltage supplied to the controlled device should be monitored by the fault line.
This DTC is used to indicate that the Alternative Fuels ECM fault line has monitored a control circuit fault.
Monitored control circuits include the following components:
^ The Fuel Control Solenoid (FCS) control circuit
^ The Idle Control Solenoid (ICS) control circuit
^ The Alternative Fuels Operation (AFO) Signal control circuit
^ The Low Pressure Lock-Off (LPL) solenoid control circuit
^ The EVAP Canister Purge Enable Control circuit
CONDITIONS FOR RUNNING THE DTC
The ignition is ON.
CONDITIONS FOR SETTING THE DTC
The Alternative Fuels ECM monitors a control circuit fault for at least 1 second continuously.
ACTION TAKEN WHEN THE DTC SETS
^ The Alternative Fuels ECM will illuminate the MIL and store the DTC as History during 1 drive trip in which the diagnostic runs and fails.
^ The Alternative Fuels ECM will record operating conditions at the time the DTC sets. This information will be stored as Freeze Frame data.
CONDITIONS FOR CLEARING THE MIL/DTC
^ The Last Test Failed status will clear when the DTC runs and passes.
^ The Alternative Fuels ECM will turn OFF the MIL after 3 consecutive drive trips that the DTC runs and passes.
^ The History status will clear after 40 consecutive WARM-UP cycles with NO failures of ANY DTC.
^ All DTC Information can be cleared using a scan tool.
^ Interruption of Control Module (AF ECM/VCM/PCM or ECM) power or ground MAY clear DTC Information. Clearing DTC Information with this method is in-consistent and should not be performed.
DIAGNOSTIC AIDS
The scan tool Output Driver data parameters are only functional when the vehicle is operating on CNG.
Intermittent Condition
A fault not present indicates the condition that caused the DTC to set is intermittent and not currently present. Refer to the Intermittent Conditions diagnostic information located in Symptoms - Computers and Control Systems. If any additional DTCs were stored proceed to the applicable DTC table in the order stated in Diagnostic System Check - Alternative Fuels (Computers and Control Systems). Initial Inspection and Diagnostic Overview Intermittent Conditions
TEST
Steps 1-9:
Steps 10-17:
Steps 18-26:
Steps 27-37:
