SMU - Revised Speedometer and/or Odometer Innacurate or Inoperative, Tachometer Inaccurate or Inoperative Symptom Charts. Oldsmobile Aurora 2001

Subject:

Revised Speedometer and/or Odometer Inaccurate or Inoperative, Tachometer Inaccurate or Inoperative Symptom Charts

Models:

2001 Oldsmobile Aurora

This bulletin is being issued to revise the Speedometer and/or Odometer Inaccurate or Inoperative symptom chart. A test description has been added and Step 5 of this chart has been revised. Also revised is the Tachometer Inaccurate or Inoperative symptom chart. A test description has been added and Step 4 of this chart has been revised. Please use the following to replace the existing information in the Instrument Panel and Console sub-section of the Service Manual.

This information has been updated within SI2000. If you are using a paper version of this Service Manual, please mark a reference to this bulletin on the affected page in the Instrument Panel and Console sub-section of the Service Manual.

Speedometer and/or Odometer Inaccurate or Inoperative

Test Description

Step 5. This step tests the complete vehicle speed signal circuit from the PCM to the cluster, including the flat wire harness C215 to the IPC. For more information on flat wire circuits refer to Inline Harness Connector End Views in Wiring Systems.

Step	Action	Yes	No
Schematic Reference: Instrument Cluster Schematics
1	Did you perform the Instrument Cluster Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check -- Instrument Cluster
2	Install a scan tool. Raise the vehicle drive wheels. Refer to Lifting and Jacking the Vehicle in General Information. Start the engine. Place the transmission into drive. With a scan tool, observe the Vehicle Speed Sensor parameter in the PCM Engine Data 1 list. Does the Vehicle Speed Sensor parameter match the speedometer display?	Go to Step 3	Go to Step 4
3	Does the odometer work properly?	Go to Testing for Intermittent and Poor Connections in Wiring Systems	Go to Step 9
4	Turn the ignition OFF. Disconnect the PCM connector C1. Turn the ignition ON, with the engine OFF. Measure the voltage from the vehicle speed signal circuit to a good ground. Does the voltage measure greater than 9.0 volts?	Go to Step 6	Go to Step 5
5	Test the vehicle speed signal circuit for an open, for a short to ground, or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 7
6	Test the vehicle speed signal circuit for a short to battery. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 8
7	Test the ignition 1 voltage circuit of the instrument cluster for an open or for a short to ground. Refer to Testing for Intermittent and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 9
8	Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 11
9	Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 12	Go to Step 10
10	Replace the instrument panel cluster. Refer to Instrument Panel Cluster (IPC) Replacement. Did you complete the replacement?	Go to Step 12	--
11	Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls -3.5.L or to Powertrain Control Module (PCM) Replacement in Engine Controls 4.0L. Did you complete the replacement?	Go to Step 12	--
12	Operate the system in order to verify the repair. Use the scan tool in order to clear the DTC's that may have set in other modules during diagnosis. Did you correct the condition?	System OK	Go to Step 2

Tachometer Inaccurate or Inoperative

Test Description

Step 4. This step tests the complete vehicle speed signal circuit from the PCM to the cluster, including the flat wire harness C215 to the IPC. For more information on flat wire circuits refer to Inline Harness Connector End Views in Wiring Systems.

Step	Action	Yes	No
Schematic Reference: Instrument Cluster Schematics
1	Did you perform the Instrument Cluster Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check -- Instrument Cluster
2	Install a scan tool. Start the engine. With a scan tool, observe the Engine Speed parameter in the PCM Engine Data 1 list. Does the Engine Speed parameter match the tachometer display?	Go toTesting for Intermittent and Poor Connections in Wiring Systems	Go to Step 3
3	Turn the ignition OFF. Disconnect the PCM connector C2. Turn the ignition ON, with engine OFF. Measure the voltage from the engine speed signal circuit to a good ground. Does the voltage measure greater than 9.0 volts?	Go to Step 6	Go to Step 4
4	Test the engine speed signal circuit for an open, for a short to ground, or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 5
5	Test the ignition 1voltage circuit of the instrument cluster for an open or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 8
6	Test the engine speed signal circuit for a short to battery voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 7
7	Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 10
8	Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 11	Go to Step 9
9	Replace the instrument panel cluster. Refer to Instrument Panel Cluster (IPC) Replacement. Did you complete the replacement?	Go to Step 11	--
10	Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls -3.5.L or to Powertrain Control Module (PCM) Replacement in Engine Controls 4.0L. Did you complete the replacement?	Go to Step 11	--
11	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2