Hummer H3. Manual — part 1458

Is the circuit resistance less than
the specified value?

Go to Step 7

Go to Step

13

7

Test the high signal circuit and
the low signal circuit of the VSS
for being shorted together. Refer
to Circuit Testing and Wiring
Repairs .
Did you find and correct the
condition?

-

Go to Step 15

-

8

Test the high signal circuit of the
VSS for a short to ground. Refer
to Testing for Short to Ground
and Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 15 Go to Step 9

9

1. Connect PCM connector

C3.

2. Disconnect the VSS.

3. Select DC volts on the

DMM.

4. Using the J 35616 , connect

the DMM test leads to the
VSS high signal circuit and
the VSS low signal circuit
of the VSS wiring harness
connector.

5. Turn ON the ignition, with

the engine OFF.

Does the DMM display system
voltage?

-

Go to Step 10

Go to Step

12

10

Test the high signal circuit of the
VSS for a short to voltage. Refer
to Testing for a Short to
Voltage and Wiring Repairs .
Did you find and correct the
condition?

-

Go to Step 15

-

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

11

1. Test the high signal circuit

of the VSS for an open.

2. Test the low signal circuit of

the VSS for an open.

Refer to Testing for Continuity
and Wiring Repairs .Did you
find and correct a condition?

-

Go to Step 15

Go to Step

13

12

1. Remove the VSS. Refer to

Vehicle Speed Sensor
Replacement.

2. Inspect the VSS and the

transmission for the
following conditions:

Incorrect VSS

VSS damage

Excessive VSS to
speed sensor rotor gap

Incorrect speed sensor
rotor alignment

Speed sensor rotor
damage

3. Repair any of the above

conditions as necessary.

Did you complete the repair?

-

Go to Step 15

-

13

Replace the VSS. Refer to
Vehicle Speed Sensor
Replacement.
Did you complete the
replacement?

-

Go to Step 15

-

14

Replace the PCM. Refer to
Control Module References for
replacement, setup and
programming.
Did you complete the
replacement?

-

Go to Step 15

-

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

DTC P0503

Fig. 9: Vehicle Speed Sensor (VSS) Circuit Schematic

15

Perform the following procedure
in order to verify the repair:

1. Select DTC.

2. Select Clear Info.

3. Test drive the vehicle.

4. Select Specific DTC.

5. Enter DTC P0502.

Has the test run and passed?

-

Go to Step 16 Go to Step 2

16

With the scan tool, observe the
stored information, capture info
and DTC info.
Does the scan tool display any
DTCs that you have not
diagnosed?

-

Go to
Diagnostic
Trouble Code
(DTC) List -
Vehicle

System OK

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

Courtesy of GENERAL MOTORS CORP.

Circuit Description

The vehicle speed sensor (VSS) assembly provides vehicle speed information to the powertrain
control module (PCM). The VSS assembly is a permanent magnet generator. The VSS produces
alternating current (AC) as the rotor teeth on the output shaft of the transmission, 2WD or transfer
case, 4WD, pass through the magnetic field of the sensor. The frequency and amplitude of the AC
waveform increase as vehicle speed increases.

If the PCM detects no vehicle speed for a specified length of time, while other sensors indicate
that the vehicle is moving, DTC P0503 sets. DTC P0503 is a type B DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0503 Vehicle Speed Sensor (VSS) Circuit Intermittent

Conditions for Running the DTC

No VSS DTCs P0502.

The engine speed is 450-6,800 RPM for 8 seconds.

The system voltage is 10-18 V.

The time since the last gear change is 6 seconds or more.

The time since the last transfer case gear change is 3 seconds or more.

The engine speed change is more than 500 RPM in 2 seconds.

Conditions for Setting the DTC

The transmission output speed must drop by 1,500 RPM in 0.5 seconds.

Action Taken When the DTC Sets

The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive
trip in which the Conditions for Setting the DTC are met.

The PCM disables Cruise Control.

The PCM records the operating conditions when the Conditions for Setting the DTC are
met. The PCM stores this information as Freeze Frame and Failure Records.

The PCM stores DTC P0503 in PCM history during the second consecutive trip in which
the Conditions for Setting the DTC are met.

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3