P035

Diagnostic Trouble Code Chart P035:

Ignition Control Circuit:

CIRCUIT DESCRIPTION
The diagnostic test monitors the REF LO voltage (CKT 453) input to the Powertrain Control Module (PCM) and sets the code if the voltage difference between REF LO and PCM power ground is greater than certain preset values.

The PCM internally adds 2.5 volts to the REF LO signal. If the voltage is above 3.98 volts or below 1.04 volts it is considered out of range and Code P035 is set.

TEST CONDITION
Code P016 not set.

FAILURE CONDITIONS
1. Voltage difference between PCM ground and Ignition Control Module REF LO 1.48 volts or greater for 1 second.
OR
2. Voltage difference between PCM ground and Ignition Control Module REF LO 1.46 volts or less for 1 second.

ACTION TAKEN
None

NOTES ON FAULT TREE
1. If the value of PD09 is 1.1 volt or less, this means that the PCM ground voltage is floating high causing P035 to set.
2. Checking for a short to voltage on CKT 453.
3. 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 ground through the REF LO input to the PCM.

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