During certain conditions such as long term vehicle storage, the drive motor battery may discharge to such a state that cranking of the engine is not possible.
Jump Assist is a procedure that allows the accessory DC power control module (APM) to convert 12V energy into 300V energy to charge the drive motor battery. Jump Assist is initiated with a scan tool output control. For the duration of the Jump Assist Procedure, the APM, hybrid powertrain control module (HPCM) and the battery energy control module (BECM) remain awake and communicating while the ignition is OFF.
Jump Assist Description and Operation
• | Tech 2 Scan Tool |
• | 12 Volt DC Battery Charger rated at greater than 20 amps continuous |
Warning: High temperatures may result from failure to make a secure electrical connection. This could result in the potential for personal injury and damage to the vehicle and/or charger due to the extended period of time of operation and high currents involved with Jump-Assist.
⇒ | If the voltage is less than 194 volts, Jump Assist will not initiate and the drive motor generator battery must be replaced. Refer to Drive Motor Generator Battery Replacement. |
⇒ | If the parameters are not within the specification, the high voltage contactor relays have not closed. Diagnose the DTCs that have opened the high voltage contactor relays. Refer to Diagnostic System Check - Vehicle. |
4.1. | Initiate the APM Jump Assist output control with the scan tool. You should observe the READY message on the DIC. |
4.2. | Turn the scan tool OFF. |
4.3. | Turn the ignition key to the OFF position. |
⇒ | Jump Assist will initiate and a transfer of energy between the 12 volt DC battery charger and the drive motor generator battery will occur through the APM. The DIC should display "JUMP ASSIST ACTIVE BATTERY CHARGING". |
Note: The scan tool may be removed from the vehicle at this time if desired and the Jump Assist will continue.
⇒ | If the estimated time has elapsed or the DIC displays the "JUMP ASSIST COMPLETE" message the drive motor battery should have sufficient charge to start the engine. |
⇒ | If the DIC displays the "JUMP ASSIST ABORTED" message, one of the following conditions has occurred. Repair the condition and restart Jump Assist if necessary. |
• | The 12 volt circuit was not maintained at greater than 11.0 volts |
• | The HPCM stored a DTC which resulted in the opening of the high voltage contactor relays |
• | The drive motor generator battery voltage is greater than 358 volts or less than 180 volts |
• | The ignition key was turned to the RUN position while the Jump Assist output control was active |
⇒ | If the engine cranks and runs, drive the vehicle for at least 20 minutes to allow the BECM to relearn drive motor battery state of charge. |
⇒ | If the engine does not crank, refer to Engine Will Not Crank. |
Calc. Hybrid Battery Current (Amps)* | Time (Minutes) |
---|---|
0.25 Amps | 228 minutes |
0.50 Amps | 114 minutes |
0.90 Amps | 63 minutes |
1.40 Amps | 41 minutes |
1.90 Amps | 30 minutes |
2.40 Amps | 24 minutes |
2.90 Amps | 20 minutes |
*Depending upon model year, hybrid battery current may be displayed as a negative value when charging during Jump Assist. |