Powertrain Controls - ECM/PCM

No Ignition Signal - Part 1 Of 2:

No Ignition Signal - Part 2 Of 2:

RPM Signal Circuit:

Circuit Description:
The powertrain control module (PCM) provides 5 volts to the igniter. The igniter in turn processes this voltage and returns it to the PCM as a signal (Ignition Fail-Safe Signal). The PCM also receives a 0.70 volt signal (Ignition Signal) when the starter is being cranked. The PCM uses these signals, along with others, to determine when to energize the fuel injectors.

DTC 14 will set if the following condition is met:
^ Ignition fail-safe signal is not received at the PCM for four consecutive ignition signals.

Test Description:
Numbers below refer to circled numbers on the diagnostic chart.

1. This checks for the 5 volts from the PCM.

2. Verifies the 0.10 - 2.0 volt signal from the PCM.

3. Checks to see if voltage is supplied to the distributor.

4. Checks for an open in BLK/ORN wire between junction block 1 and distributor or for a faulty junction block 1.

5. This checks for opens in the power feed to the igniter for a faulty ignition coil and for a faulty igniter.

6. This checks for an open in the RED/BLK or BLK/ORN wire to the ignition switch and for a faulty ignition switch.

Diagnostic Aids:
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect hamess connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.