DTC 16

Code 16 Diagnostic Chart:

PCM Power Supply And Diagnostic Circuit Diagram:

CIRCUIT DESCRIPTION:
The PCM monitors battery or system voltage on circuit 439 to terminal "BA2". If the PCM detects voltage above 17 volts or below 9 volts for more than 10 seconds, it will turn the SERVICE ENGINE SOON light on and set Code 16 in memory.

NOTE: If Code 16 is set, the transmission will be forced onto 3rd gear, to avoid erratic shifting due to incorrect system voltage.

TEST DESCRIPTION
Numbers below refer to circled numbers 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. Normal charging system voltage is 13.5 - 14.2 volts. If less than 9 volts or over 17 volts, repair generator.

DIAGNOSTIC AIDS:
^ An intermittent may be caused by a poor connection, rubbed through insulation, a wire broken inside the insulation or poor PCM grounds.

Check For:

^ Poor Connection or Damaged Harness. Inspect PCM harness connectors for backed out terminal "BA2", improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.

^ Intermittent Test. If connections and harness check OK, monitor battery voltage display while moving related connectors. If the failure is induced, the battery voltage will abruptly change. This may help to isolate the location of the malfunction. An engine stall while manipulating the harness indicates that the PCM has lost voltage at terminal "BA2". Check for loose connectors in circuit 439.

NOTE: Starting the engine while charging battery with a battery charger may set a Code 16.