DTC Descriptor
DTC B0560: Tachometer CircuitDiagnostic Fault Information
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Engine Speed Signal Circuit | B0560 | B0560 | B0560 | -- |
Circuit Description
The instrument panel cluster (IPC) receives the engine speed information from the engine control module (ECM)/powertrain control module (PCM) through the engine speed signal circuit. The ECM/PCM converts the data from the engine speed sensor to a 2 pulses/(engine revolution) signal. The ECM/PCM also sends a class 2 message to the IPC indicating the engine speed. If the IPC determines there is a loss of the engine speed signal from the ECM/PCM due to a engine speed signal circuit malfunction, a DTC sets.
Conditions for Running the DTC
| • | The engine speed is greater than 800 RPM. |
| • | The ignition voltage is greater than 9 volts, but less than 18 volts. |
Conditions for Setting the DTC
| • | The IPC detects that the engine speed signal circuit does not match the engine speed from the class 2 serial data circuit. |
| • | The above condition is present for at least 5 seconds. |
Action Taken When the DTC Sets
The IPC stores the DTC in memory.
Conditions for Clearing the DTC
| • | A last test failed (current DTC) clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 100 consecutive malfunction-free warm-up cycles. |
| • | The IPC receives the clear code command from the scan tool. |
Reference Information
Schematic Reference
| • | Engine Controls Schematics for the 4.2L engine |
| • | Engine Controls Schematics for the 5.3L engine |
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the ECM/PCM. Install a signal generator and instrument panel tester between the engine speed signal circuit and ground.
- Ignition ON, set the signal generator to generate a tachometer signal. Verify that the tachometer indicates a RPM reading.
- If all circuits test normal, test or replace the ECM/PCM.
| ⇒ | If no RPM reading is present, test the signal circuit for an open/high resistance, a short to voltage, or a short to ground. If the circuit tests normal, replace the IPC. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the ECM/PCM and IPC replacement, setup, and programming
