DTC 41

DTC 41 1X Signal Error:

1X Signal Error:

CIRCUIT DESCRIPTION
The Ignition Control Module (ICM) processes the 1X signal and sends it to the PCM for Alternate Synchronous Double Fire (ASDF) firing (1-4) and then (2-3) of the fuel injector. This is done for cleaner emissions.

DTC 41 WILL SET WHEN
Loss of 1X signal will trigger Simultaneous Synchronous Double Fire (SSDF) firing (1, 2, 3, 4, all at the same time) of the injectors and a DTC 41 will be set.

ACTION TAKEN (PCM WILL DEFAULT TO)
The PCM will turn "ON" the MIL (Malfunction Indicator Lamp).

DTC 41 WILL CLEAR WHEN
Conditions for fault are no longer present and Tech 1 "Clear DTCs" function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and fuse #9 is removed for 10 seconds.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step will determine if DTC 41 is the result of a hard failure or an intermittent condition.
2. Checks 5V out of ignition control module.
3. Checks CKT 1579 for short, open or short to voltage.
4. Checks connections at ignition control module and the ignition control module itself.

DIAGNOSTIC AIDS
Positive I.D. of replacement ignition control module is essential as physical appearance is identical to other ignition control module.