P1500

Wiring Diagram:

Circuit Description
While the engine is being cranked, the battery voltage is applied to the Powertrain Control Module (PCM). The starter signal is mainly used to increase the fuel injection volume for the starting injection control. This signal is sent from the transmission range switch (automatic transmission) or the Clutch Pedal Position (CPP) switch. If this signal is not detected during ignition, the PCM will still allow the engine to start.

Conditions for Setting the DTC
^ No signal to the PCM with the starter engaged.
^ Low voltage at the PCM while cranking the engine.
^ High voltage at the PCM after starting the engine.

Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC
^ The MIL will turn off after three consecutive drive cycles without a fault present.
^ A DTC will clear after 40 consecutive warm-up cycles without a fault.
^ The DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for a poor connection or a damaged wiring harness. Inspect the wiring harness for problems and repair as necessary.
If a DTC P1500 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

Test Description
The numbers below refer to the step numbers in the Diagnostic Table.
1. The Powertrain (OBD) System Check prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. This step determines if a fault is present.
3. This step checks for the correct voltage on the crank signal circuit. While the engine is cranking, the PCM crank signal terminal should have a voltage reading of 6 to 12 volts and after the engine is started, the PCM crank signal terminal should have a voltage reading of 0 volts.