DTC 32

DTC 32 Chart:

Exhaust Gas Recirculation (EGR) Flow Check:

CIRCUIT DESCRIPTION
The Exhaust Gas Recirculation (EGR) system is controlled by the Powertrain Control Module (PCM). The PCM controls the vacuum being supplied to the valve by energizing and de-energizing a solenoid.

The PCM uses information from various engine sensors to determine when EGR is necessary. Once the PCM has requested EGR by grounding the solenoid circuit, the PCM will monitor engine operating conditions to determine if exhaust gas flow has entered the intake manifold. When the PCM tests for EGR operation and no change in engine operating conditions are indicated, a DTC will set.

DIAGNOSTIC TROUBLE CODE (DTC) 32 WILL SET WHEN
The PCM does not see a change in Manifold Absolute Pressure (MAP) when EGR test is executed, based on current BARO value under the following conditions.

^ Manifold vacuum is between 33 and 60 kpa (9.7 to 17.7 in. HG)
^ Vehicle speed Sensor (VSS) is greater than 40 mph.
^ Transmission is in 4th or 5th gear (M/T).
^ DTC(s) 21, 22, 33, or 34 is not set.
^ Torque Converter Clutch (TCC) is locked (A/T).

ACTION TAKEN (PCM WILL DEFAULT TO)
The Malfunction Indicator Lamp (MIL) will illuminate, the EGR system will go into "Open Loop," and the cooling fan will enable.

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

1. Intake passage: Shut the engine "OFF" and remove the EGR valve from the manifold. Plug the exhaust side hole with a suitable stopper. Leaving the intake side hole open, attempt to start the engine. If the engine runs at a high idle (up to 3000 RPM is possible) or starts and stalls, the EGR intake passage is not restricted. If the engine starts and idles normally, the EGR intake passage is restricted.

Exhaust passage: With EGR valve still removed plug the intake side hole with a suitable stopper. With the exhaust side hole open, check for the presence of exhaust gas. If exhaust gas is not present the EGR exhaust side passage is restricted.

NOTICE:
Be sure shop exhaust hose is not connected during steps 2 & 3.

2. The remaining test checks the ability of the EGR valve to interact with the exhaust system. This system uses a negative backpressure EGR valve which should hold vacuum with engine "OFF."
3. When the engine is started, exhaust backpressure at the base of the EGR valve should open the valve's internal bleed and vent the applied vacuum allowing the valve to seat. BECAUSE THE SHOP EXHAUST HOSE IS NOT INSTALLED AT THIS TIME. DO NOT ALLOW THE ENGINE TO RUN LONGER THAN 15 SECONDS.

DIAGNOSTIC AIDS
^ Vacuum lines should be thoroughly checked for proper routing. Refer to Emission Control Information label.
Emission Control Information Label
^ If problems continue Refer to Chart - C7 to diagnose EGR system.
Chart C-7 Exhaust Gas Recirculation (EGR) System Check
^ DTC 32 diagnosis only the mechanical part of the EGR system. The electrical portion is handled by DTC 27.