Powertrain Control Module Controlled Tachometer Diagnosis. Buick Century 1998

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1998 🢒 Century 🢒 Engine 🢒 Engine Controls - 3.1L 🢒 Powertrain Control Module Controlled Tachometer Diagnosis

Refer to

The PCM controls the pulse frequency in relationship to engine RPM, and sends the information class II to the Instrument Cluster.

Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console for additional diagnostic information.

Check for the following conditions:

•	Poor connection at the PCM or instrument cluster. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

•	Damaged harness. Inspect the wiring harness for damage.

Step	Action	Value(s)	Yes	No
1	Was Instrument Cluster diagnosis performed?	--	Go to Step 2	Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console
2	Was the Powertrain On-Board Diagnostic System Check performed?	--	Go to Step 3	Go to Powertrain On Board Diagnostic (OBD) System Check
3	Are there any DTCs set?	--	Go to applicable DTCs	Go to Step 4
4	Install scan tool. Start the engine. Observe the engine RPM on the scan tool. Does the scan tool RPM match the Instrument Cluster?	--	System OK Go to Diagnostic Aids	Go to Step 5
5	Verify proper operation of scan tool. Connect scan tool to another vehicle and observe the RPM. Does scan tool match vehicle RPM?	--	Go to Tachometer Inaccurate in Instrument Panel, Gauges and Console	System OK Refer to Diagnostic Aids