B0560

DTC B0560

DTC Descriptors

DTC B0560
- Tachometer Circuit

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit/System Description

The engine control module (ECM) creates the engine speed signal by pulsing the engine speed signal circuit to ground at a rate of 2 pulses per engine revolution. The instrument panel cluster (IPC) converts the engine speed signal to a tachometer position to indicate the engine speed. The IPC also receives from the ECM a class 2 message indicating the engine speed. The IPC uses the class 2 engine speed information from the ECM for diagnostic purposes.

Conditions for Running the DTC

* The IPC receives a class2 message from the ECM indicating the engine speed is greater than 800 RPM
* The ignition voltage is between 9-18 volts.

Conditions for Setting the DTC

* The IPC does not detect a 2 pulses per engine revolution signal on the engine speed signal circuit.
* The above condition is present for at least 5 seconds.

Action Taken When the DTC Sets

The IPC stores DTC B0560 in memory.

Conditions for Clearing the DTC

* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.
* The IPC receives a clear code command from the scan tool.

Circuit/System Testing

1. Ignition ON, with the scan tool installed, perform the IPC Gage Sweep Test in the IPC Output Controls. Verify the tachometer dial moves from the minimum to the maximum position and back to the tachometer minimum position.

• If the tachometer does not perform the IPC Gage Sweep Test, replace the IPC.

2. Ignition OFF, disconnect the C1 harness connector at the engine control module (ECM).
3. Ignition ON, test for 9 - 11 volts between the engine speed signal circuit and ground.

• If less than 9 volts test the engine speed signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPC.

• If greater than 11 volts, test the engine speed signal circuit for a short to voltage.

4. If all circuits test normal, test or replace the ECM.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Refer to Programming and Relearning.Programming and Relearning