Powertrain Controls - ECM/PCM

DTC 36 Chart (1 Of 2):

DTC 36 Chart (2 Of 2):

EGR System Circuit:

CIRCUIT DESCRIPTION
The PCM command moves the Exhaust Gas Recirculation (EGR) valve idle to the desired position with EGR valve control CKT 435, PCM then monitors the scaled EGR feedback CKT 1456 to determine if the EGR valve actual pintle position is within 10 percent of the EGR desired pintle position. The PCM also monitors the raw EGR valve pintle closed position with ignition "ON" and engine "OFF" which should be between 0.2 and 2.0 volts (learned EGR closed position). If the PCM detects more than 10 percent difference between EGR desired pintle and EGR actual position, or if the PCM detects less than 0.2 volt or more than 2.0 volt on EGR feedback circuit with the ignition "ON" and engine "OFF," DTC 36 will set.

DTC 36 WILL SET WHEN
- Ignition voltage is 11 volts or greater.
- Difference between desired and actual EGR pintle position is greater than 10 percent.
OR
- Learned EGR closed position is less than 0.2 volt or greater than 2.0 volts.

ACTION TAKEN (PCM WILL DEFAULT TO)
With a current DTC 36 set, the PCM will illuminate the Malfunction Indicator Lamp (MIL) (Service Engine Soon) and disable the EGR system for the entire ignition cycle.

DTC 36 WILL CLEAR WHEN
The fault no longer exists and ignition switch is cycled "OFF"and "ON."

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

1. Checks for an EGR valve sticking partially open or an incorrect pintle position sensor feedback signal.
2. Ensures that the PCM is capable of controlling EGR pintle position and is reading the pintle position feedback signal properly.
3. Checks the EGR valve driver in the PCM and CKT 435.
4. The checks on this part of the chart will diagnose an incorrect EGR pintle position sensor input signal. This test verifies a 5 volt reference at the EGR valve.
5. Ensures that CKT 1456 is not shorted to ground.
6. Checks CKT 1456 for an open.

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside the insulation.
Check for:

Poor connection or damaged harness
Inspect PCM harness connectors for backed out terminals "A4", "C1", "E16", or "C9", improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.

Intermittent test
If connections and harness check OK, monitor a digital voltmeter connected between affected terminals and ground while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change.