P1500

DTC P1500 Starter Signal Circuit:

Starter:

CIRCUIT DESCRIPTION

While the engine is being cranked, the battery voltage is applied to the Engine Control Module (ECM). 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 ECM will still allow the engine to start.


CONDITIONS FOR SETTING THE DTC

- No signal to the ECM with the starter engaged.

- Low voltage at the ECM while cranking the engine.

- High voltage at the ECM 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 ECM 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.

- DTC(s) can be cleared by using a scan tool or by disconnecting the ECM 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 last set. This may assist in determining how often the DTC sets.

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 Engine 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 ECM (Crank Signal terminal) should have a voltage reading of 6 to 12 volts and after the engine is started the ECM should have a voltage reading of 0 volts.