• | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Engine Speed Signal | B0560 | B0560 | B0560 | -- |
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 serial data message indicating the engine speed. The IPC uses the serial data engine speed information from the ECM for diagnostic purposes.
• | The engine speed is greater than 800 RPM. |
• | The ignition voltage is between 9-18 volts. |
• | The IPC detects that the engine speed signal circuit does not match the engine speed from the serial data circuit. |
• | The above condition is present for at least 5 seconds. |
The IPC stores the DTC in memory.
• | A last test failed (current DTC) clears when the diagnostic runs and does not fail. |
• | A history DTC clears after 40 malfunction-free warm-up cycles. |
Instrument Cluster Description and Operation
Control Module References for scan tool information
⇒ | If no RPM reading is present, test the signal circuit for a short to voltage, a short to ground or an open/high resistance. If the circuit tests normal, replace the IPC. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the ECM and IPC replacement, setup, and programming