Powertrain Controls - ECM/PCM

DTC 35 Chart:

Ignition System Circuit:

CIRCUIT DESCRIPTION
The PCM applies 2.5 volts to the reference low CKT 453 from Ignition Control (IC) module to calculate the ground difference between the IC module and PCM. If the PCM detects a voltage signal on CKT 453 greater than 3.98 volts or less than 1.04 volts, DTC 35 will set.

DTC 35 WILL SET WHEN
- DTC 16 is not set.
- Reference low signal voltage is greater than 3.98 volts for 1 second or more.
OR
- Reference low signal voltage is less than 1.04 volt for 1 second or more.

ACTION TAKEN (PCM WILL DEFAULT TO)
DTC 35 does not illuminate the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

DTC 35 WILL CLEAR WHEN
The fault no longer exists.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. If Tech 1 displays 1.1 volts or less, this means that the PCM ground voltage is high causing DTC 35 to set.
2. Checking for a short to voltage on CKT 453.
3. Checking for an open in CKT 453.
4. Voltage measured at ignition control module connector "C4" terminal "F" should be less than 0.1 volt. If the voltage is higher, then the module must have a bad ground causing the module to try to ground through the REF LO input to the PCM.

DIAGNOSTIC AIDS
This code may set due to an improperly installed PCM. This may cause the PCM to not be electrically isolated from the body ground.