P1500

Starter Signal Circuit:

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 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.

^ Once per drive cycle for 0.4 seconds.

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 consecutively passing cycles without a fault present.

^ A History DTC will clear after 40 consecutive warm-up cycles without a fault.

^ DTC(s) can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

^ Poor connection or damaged harness. Inspect the wiring harness for damage.

If 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.

If any wiring repairs need to be made, Refer to Repair Procedures in Diagrams.

Test Description

Number(s) below refer to the step number(s) on 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. Determine if a fault is present.

3. While the engine is cranking the PCM (Engine Start Signal terminal) should have a voltage reading of 8 to 12 volts and after the engine is started the PCM should have a voltage reading of 0 volts.

5. If voltage stays high after the engine is started, check for a short to voltage on the Engine Start Signal circuit.