B0560

DTC B0560

Diagnostic Instructions

* Perform The Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B0560
- Tachometer Circuit

Diagnostic Fault Information






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 engine speed signal circuit is pulled high to B+ in the instrument panel cluster (IPC). 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 class 2 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.

Circuit/System Testing

1. Ignition ON, with the scan tool, 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 ECM.
3. Ignition ON, test for 9-11 volts between the engine speed signal circuit terminal 25 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

Perform The Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

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