• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage (PWR/TRN Relay) | P1516, P1682 | P1516, P1682, P2101 | P0690 | -- |
Ignition 1 Voltage (IGN Relay) | -- | ¹ | P0575, P0650 | -- |
¹This fault results in a no crank, no start condition. |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Ignition ON Engine OFF. PWR/TRN Relay commanded ON | |||
Ignition 1 voltage | 0 volts | 0 volts | 12 volts |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Ignition ON Engine OFF. IGN Relay commanded ON | |||
Ignition 1 voltage | 0 volts | 0 volts | 12 volts |
There are 2 ignition 1 voltage circuits supplied to the engine control module (ECM). The first ignition 1 voltage circuit is provided by the PWR/TRN relay, through a fuse. This ignition 1 voltage circuit supplies power to all the internal ECM circuits associated with the throttle actuator control (TAC) operation. The IGN relay provides the second ignition 1 voltage circuit to the ECM, through a fuse. This ignition 1 voltage provides power to other internal ECM circuits, except those associated with TAC operation. The ECM continuously monitors the voltage level difference between the 2 circuits.
• | The ignition is in the Unlock/Accessory, Run, or Crank position. |
• | System voltage is more than 5.23 volts. |
• | Powertrain relay is commanded ON. |
• | DTC P1682 runs continuously when the above conditions are met. |
The ignition 1 voltage of the Run/Crank relay is more than 3 volts different than the ignition 1 voltage of the powertrain relay for more than 1 second.
• | DTC P1682 is a Type A DTC. |
• | The engine may operate in a reduced engine power mode. |
DTC P1682 is a Type A DTC.
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test.
Engine Control Module Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp illuminates, test the ignition circuit for a short to voltage. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the circuit for an open/high resistance and a short to ground. If the circuit tests normal and its fuse is open, replace the ECM. |
⇒ | If the parameter does not indicate B+ voltage, test the ignition circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If not the specified value, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming