DTC 12

Code Chart 12 And/Or 13:

Ignition Circuit:

CIRCUIT DESCRIPTION:

The ECM supplies a voltage to the pick-up coil. As the stator inside the distributor passes the pick-up coil the voltage signal is pulled low. This low voltage (signal) is then used to sequence the fuel injector. If this signal is not present for 2 seconds, Code 12 and 13 will set.

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. Voltage is supplied by the ECM to the pick-up coil.

2. Determines if rpm signal is present at the ECM.

3. Checks for proper resistance of the pick-up coil.

4. Checks for proper resistance of the signal rotor coil.

DIAGNOSTIC AIDS:

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Inspect ECM harness connectors for backed out terminals, NE, GO+, GO-, 1GT, 1GF, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.