Lumina V6-3.1L VIN J (2000)
DIAGNOSTIC AIDS
Inspect for the following conditions:
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Monitor the MAP sensor using a scan tool. If the MAP sensor does not respond to throttle changes, inspect the 3X reference circuits from the
ignition control module to the PCM.
If the 3X reference signal is lost the PCM will only update the MAP sensor reading once per key cycle, when the engine is first started.
Depending on where the MAP sensor voltage (high voltage or low voltage) is when the engine is started, the high or low voltage MAP sensor
DTCs will set.
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Inspect for kinked and damaged vacuum hoses, ensure that a good vacuum source is available. Refer to Emission Hose Routing Diagram.
IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or
replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
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Poor terminal connection.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty
terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor
Connections and Connector Repairs in Diagrams.
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Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring
harnesses related to the sensor. A change in the display may indicate the location of the fault. Refer to Circuit Testing and Wiring Repairs in
Diagrams.
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Inspect the PCM and the engine grounds for clean and secure connections.
If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.
