Refer to
EBCM, Generator, PCM, Tachometer
.
Circuit Description
The Powertrain Control Module (PCM) controls the pulse frequency in relationship to engine RPM, and sends the information class 2 to the instrument cluster.
Diagnostic Aids
Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console for additional diagnostic information.
Inspect for the following conditions:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
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.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Step | Action | Values | Yes | No | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check--Instrument Cluster? | -- | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console | |||||||||||||||
2 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||||||||||
3 | Are there any DTCs set? | -- | ||||||||||||||||
4 |
Does the scan tool RPM match the instrument cluster? | -- | Go to Diagnostic Aids | |||||||||||||||
5 |
Does the scan tool match vehicle RPM? | -- | Go to Scan Tool Does Not Power Up or Scan Tool Does Not Communicate with Class 2 Data Line in Data Link Communications | |||||||||||||||
6 |
Does the scan tool indicate correct engine speed up to 1600 RPM? | -- | Go to Tachometer Inaccurate or Tachometer Inoperative in Instrument Panel, Gauges and Console | |||||||||||||||
7 | Inspect for the following circuit conditions:
Did you find and correct the condition? | -- | System OK |
