Flag 54

Diagnostic Chart:

Circuit Schematic:

FIVE VOLT REFERENCE GROUNDED
The five volt reference circuit provides a signal voltage to the linear EGR, MAP sensor, and TP sensor. The return line is grounded through the PCM. Information flag 54 detects a short to ground in any of the three, five volt reference circuits or inside the PCM.

INFORMATION FLAG PARAMETERS

Information flag 54 will set if:
^ MAP sensor signal is zero.
^ TP sensor signal is zero.
^ Linear EGR sensor signal is zero.

DIAGNOSTIC AIDS
When attempting to diagnose an intermittent problem, use the Scan tool[1] to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

Intermittents or opens suspected to be at the connector can be detected by using Diagnostic Service Probe.

Voltage can be read on both wires without disconnecting any connectors.

Check the tightness of the female terminal grip with a spare male terminal.

The engine must meet the flag setting conditions in order to diagnose the code.

NOTE: Information flags should be used for diagnostic purposes only. They do not necessarily indicate component malfunction/failure.

[1] Select Malfunction History from Scan tool Engine Control (EC) menu.