Powertrain Controls - ECM/PCM

DTC 16 Chart:

System Voltage Circuit:

Circuit Description:
The PCM will perform a test of the ignition voltage applied to pin "C3" of the PCM. A comparison is done between the voltage applied to the input and a calibrated voltage value.

During the time a low voltage failure is present, all PCM outputs will become disabled. This may result in the additional setting of other seemingly unrelated DTCs.

DTC 16 Will Set When:
The PCM detects 8 volts or lesson the ignition feed CKT 439, engine speed is greater than 1000 RPM with both conditions met for 2 seconds.

Action Taken (PCM will default to):
The MIL will become illuminated.

DTC 16 Will Clear When:
A current DTC 16 will clear when ignition feed voltage is detected above 8 volts. A history DTC 16 will clear after 50 consecutive ignition key cycles without a current DTC 16 being stored.

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.

1. Test generator output to determine proper operation of the voltage regulator. Run engine at moderate speed and measure voltage across the battery. If less than 8 volts, repair generator.

Diagnostic Aids:
An intermittent may be caused by poor connections, chaffed insulation, a wire broken inside the insulation or poor PCM grounds.

- Intermittent test. Monitor "System Volts" display with a Tech 1 while moving related connectors. If the failure is induced, the display will abruptly change. This may help to isolate the location of the malfunction.