Circuit Description
The Powertrain Control Module (PCM) monitors the ignition voltage on the ignition feed #2 circuit to the PCM. A system voltage DTC will set whenever the voltage is above or below a calibrated value.
Conditions for Setting the DTC
The ignition voltage is greater 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 poor 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.
-
The Powertrain 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 captured when this DTC set. The scan tool stores this data for later reference.
-
Reprogram the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Techline procedures for PCM reprogramming.
-
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 greater 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 Powertrain Control Module Controlled Generator Diagnosis | |
Important : The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Did yo complete the repair? | -- | -- | ||
5 |
Does the scan tool indicate that this diagnostic has 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 the applicable DTC table | System OK |
