Hummer H2. Manual — part 370

DTC P0608

Circuit Description

The powertrain control module (PCM) creates the vehicle speed output signal by pulsing the circuit to ground.
The PCM monitors the voltage on the vehicle speed output circuit. If the PCM determines that the voltage is out
of the normal operating range, a DTC sets.

Conditions for Running the DTC

z

The engine speed is more than 400 RPM.

z

The ignition voltage is between 6.0-18.0 volts.

Conditions for Setting the DTC

6

2. Test the low reference circuit of the EOP sensor for an

open 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 8

7

Inspect for poor connections at the harness connector of the
EOP sensor. Refer to Testing for Intermittent Conditions
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

8

Inspect for poor connections at the harness connector of the
PCM. Refer to Testing for Intermittent Conditions 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

9

Replace the EOP sensor. Refer to Engine Oil Pressure
Sensor and/or Switch Replacement in Engine Mechanical.
Did you complete the replacement?

-

Go to

Step

11

-

10

Replace the PCM. Refer to Powertrain Control Module
(PCM) Replacement in Engine Controls-6.0L (LQ4).Did
you complete the replacement?

IMPORTANT:

Program the replacement PCM.

-

Go to

Step

11

-

11

1. Use the scan tool in order to clear the DTCs.

2. Operate the vehicle within the Conditions for Running

the DTC.

Does the DTC reset?

-

Go to

Step 2

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

z

The PCM detects that the commanded state of the driver and the actual state of the signal circuit do not
match.

z

The above condition must be present for a minimum of 5 seconds.

Action Taken When the DTC Sets

The PCM records the operating conditions at the time the diagnostic fails. The PCM displays the failure
information in the Failure Records on the scan tool.

Conditions for Clearing the MIL/DTC

z

The history DTC clears after 40 malfunction free warm-up cycles.

z

The DTC becomes history when the conditions for setting the DTC are no longer present.

z

The PCM receives the clear code command from the scan tool.

DTC P0608

Step

Action

Value

(s)

Yes

No

Schematic Reference:Instrument Cluster Schematics

1

Did you perform the instrument panel cluster
(IPC) Diagnostic System Check?

-

Go to Step 2

Go to Diagnostic

System Check -

Instrument

Cluster

2

1. Install a scan tool.

2. Raise the vehicles drive wheels. Refer

to Lifting and Jacking the Vehicle in
General Information.

3. Start the engine.

4. Place the transmission into drive for an

automatic transmission or third gear for
a manual transmission.

5. With the scan tool, observe the Vehicle

Speed Sensor parameter in the
powertrain control module (PCM)
Engine Data 1 data list.

Does the Vehicle Speed Sensor parameter
match the speedometer display?

-

Go to Testing for

Intermittent

Conditions and Poor

Connections in Wiring

Systems

Go to Step 3

3

1. Turn OFF the ignition.

2. Disconnect the PCM connector C2.

3. Turn ON the ignition, with the engine

OFF.

4. Measure the voltage from the vehicle

9.5 V

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

DTC P0654

speed signal circuit of the PCM to a
good ground.

Does the voltage measure greater than the
specified value?

Go to Step 4

Go to Step 5

4

Test the vehicle 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 10

Go to Step 6

5

Test the vehicle speed signal circuit for an
open, for a short to voltage, 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 10

Go to Step 7

6

Inspect for poor connections at harness
connector of the PCM. Refer to Testing for
Intermittent Conditions and Poor
Connections and to Connector Repairs in
Wiring Systems.
Did you find and correct the condition?

-

Go to Step 10

Go to Step 8

7

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

-

Go to Step 10

Go to Step 9

8

Replace the PCM. Refer to Powertrain
Control Module (PCM) Replacement in
Engine Controls-6.0L (LQ4).Did you
complete the replacement?

IMPORTANT:

Program the replacement PCM.

-

Go to Step 10

-

9

Replace the IPC. Refer to Instrument Panel
Cluster (IPC) Replacement .
Did you complete the replacement?

-

Go to Step 10

-

10

1. Use the scan tool in order to clear the

DTCs.

2. Operate vehicle within the Conditions

for Running this DTC.

Does the DTC reset?

-

Go to Step 2

System OK

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2

Circuit Description

The powertrain control module (PCM) creates the engine speed signal by pulsing the circuit to ground. The
PCM monitors the voltage on the engine speed signal circuit. If the PCM determines that the voltage is not
within the normal operating range, the PCM sets a DTC.

Conditions for Running the DTC

z

The engine speed is greater than 400 RPM.

z

The ignition voltage is greater than 6 volts, but less than 18 volts.

Conditions for Setting the DTC

z

The PCM detects that the commanded state of the driver and the actual state of the signal circuit do not
match.

z

The above condition exists for a minimum of 5.0 seconds.

Action Taken When the DTC Sets

z

The PCM stores the DTC information in memory when the diagnostic test runs and fails.

z

The malfunction indicator lamp (MIL) will not illuminate.

z

The PCM records the operating conditions at the time when the diagnostic test fails. The PCM stores this
information in the Failure Records.

Conditions for Clearing the MIL/DTC

z

The DTC becomes history when the conditions for setting the DTC are no longer present.

z

A history DTC is cleared after 40 consecutive malfunction free warm-up cycles.

z

The PCM receives the clear code command from the scan tool.

DTC P0654

Step

Action

Yes

No

Schematic Reference:Instrument Cluster Schematics

1

Did you perform the instrument panel cluster
(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 powertrain control
module (PCM) Engine Data 1 data list.

Does the Engine Speed parameter match the

Go to Testing for

Intermittent Conditions

and Poor Connections in

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Instrument Panel, Gauges, and Console - Hummer H2