Circuit Description
The Powertrain Control Module (PCM) monitors the ignition voltage on the ignition positive voltage circuit to the PCM. A system voltage DTC will set whenever the voltage is more than or less than a calibrated value.
Conditions for Running the DTC
VSS is more than 8.045 km/n (5 MPH)
Conditions for Setting the DTC
The ignition voltage is more than 17 volts.
Action Taken When the DTC Sets
| • | The PCM will record the operating conditions at the time during which the diagnostic fails. This information will store in the Failure Records buffer. |
| • | A history DTC stores. |
| • | All of the outputs will disable. |
| • | The coolant fan turns ON. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
| • | Charging the battery with a battery charger and starting the engine can cause a DTC to set. |
| • | If the DTC sets when you operate an accessory, check for a faulty connection or an excessive current draw. |
| • | Additional DTCs can set as the result of the PCM disabling the outputs. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The Powertrain On-Board Diagnostic (OBD) System Check prompts you to complete some of the basic checks and to store the Freeze Frame and Failure Records data on the scan tool, if applicable. This creates an electronic copy of the data that was captured when this DTC set. The scan tool stores this data for later reference.
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Reprogram the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Techline™ procedures for PCM reprogramming and refer to the supporting material for the crankshaft position system variation learn procedure.
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If no malfunctions are present at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | |||
2 |
Is the ignition 1 voltage on the scan tool more than the specified value? | 1,400 RPM 17 V | ||
3 | Measure the battery voltage at the battery while running the engine at the specified value using a DMM. Is the battery voltage less than the specified value? | 2,000 RPM 17 V | Go to Charging System Test in Engine Electrical. | |
|
Important: Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | -- | ||
5 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||
Check to see if any DTCs are set. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to applicable DTC table | System OK |
