GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 Envoy - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC B0560

Circuit Description

The IPC monitors the engine speed signal to determine the tachometer position. If the IPC determines the engine speed signal voltage is out of the normal operating range, a DTC will set.

Conditions for Running the DTC
    • The engine speed is greater than 800 RPM.
    • The ignition voltage is greater than 9.0 volts, but less than 18 volts.

Conditions for Setting the DTC
    • The IPC detects that the commanded state of the output driver and the actual state of the control circuit do not match.
    • The above condition is present for at least 5.0 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.

Step

Action

Yes

No

Schematic Reference: Instrument Cluster Schematics

1

Did you perform the IPC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2
  1. Install a scan tool.
  2. Start the engine.
  3. With the scan tool, observe the Engine Speed parameter in the IPC Data 1 data list.

Does the Engine Speed parameter match the tachometer display?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3
  1. Turn the ignition OFF.
  2. Disconnect the PCM connector C1.
  3. Install the J 33431-C Signal Generator and Instrument Panel Tester lead to the engine speed signal circuit at the PCM harness connector, and the other lead to a good ground.
  4. Turn the ignition ON, with the engine OFF.
  5. Set the J 33431-C Signal Generator and Instrument Panel Tester to generate a tachometer signal.

Does the vehicle tachometer indicate an RPM reading?

Go to Step 5

Go to Step 4

4

Test the engine speed signal circuit for an open, a short to voltage or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

5

Inspect for poor connections at the PCM connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

6

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the replacement?

Go to Step 9

--

8

Important: Program the replacement IPC.

Replace the IPC. Refer to Instrument Cluster Replacement .

Did you complete the replacement?

Go to Step 9

--

9
  1. Use the scan tool in order to clear the DTC's.
  2. Operate vehicle within the conditions for running this DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK