Hummer H2. Manual - part 2415

Inspect for ABS DTCs. A faulty ABS condition may contribute to setting DTC P0503. 

Test Description 

The numbers below refer to the step numbers on the diagnostic table. 

3: This step tests the VSS assembly circuit.  

4: This step tests the integrity of the VSS assembly.  

DTC P0503 

Step

Action

Value

(s)

Yes

No

1

Did you perform the Diagnostic System Check - 
Engine Controls?

-

Go to Step 2

Go to Diagnostic 

System Check - 

Engine Controls 

in Engine Controls 

- 6.0L (LQ4)

2

1. Install a scan tool.  

2. Turn ON the ignition, with the engine OFF. 

3. Record the DTC Freeze Frame and Failure 

Records.  

4. Clear the DTC.  

5. Raise and support the rear axle assembly.  

6. Start the engine.  

7. Place the transmission in D3 range.  

8. With the drive wheels rotating, slowly 

accelerate to 2,000 engine RPM and hold. 
Road test the vehicle if necessary.  

Does the scan tool Transmission OSS drop or 
fluctuate more than the specified value?

IMPORTANT:

Before clearing the DTC, use the scan tool 
in order to record the Freeze Frame and 
Failure Records. Using the Clear Info 
function erases the Freeze Frame and 
Failure Records from the PCM.

1,300 

RPM

Go to Step 3

Go to Intermittent 

Conditions in 

Engine Controls - 

6.0L (LQ4)

3

1. Turn OFF the ignition.  

2. Disconnect the PCM connector C2.  

3. Using the DMM and the J 35616 GM 

Terminal Test Kit, measure the resistance 

976-

2354 

 

2004 Hummer H2 

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

 

between harness connector terminals C2-20 
and C2-21.  

Does the resistance measure within the specified 
range?

ohm

Go to Step 4

Go to Step 7

4

1. Place the transmission in NEUTRAL.  

2. Select AC volts.  

3. Prevent one rear wheel from turning.  

4. Rotate the other rear wheel by hand, ensuring 

that the driveshaft is turning.  

Does the voltage measure greater than the specified 
value?

0.5 V

Go to Step 5

Go to Step 12

5

Measure the resistance from terminal C2-21 to 
ground. 
Does the resistance measure greater than the 
specified value?

50 K 

ohm

Go to Step 6

Go to Step 9

6

1. Reconnect the PCM connector C2.  

2. Disconnect the engine wiring harness from the 

VSS assembly.  

3. Turn ON the ignition, with the engine OFF.  

4. Test the high circuit of the VSS assembly for a 

short to voltage. 

Refer to Testing for a Short to Voltage and 
extxref document="029_body-21" 
filetype="sgml" extrefid="i162420">Wiring 
Repairs in Wiring Systems. 

Did you find and correct the condition?

-

Go to Step 15

Go to Step 14

7

1. Disconnect the engine wiring harness from the 

VSS assembly.  

2. Measure the resistance of the VSS assembly.  

Does the resistance measure within the specified 
range?

976-

2354 

ohm

Go to Step 8

Go to Step 13

8

Was the resistance measured in Step 3 greater than 
the specified value?

2354 

ohm

Go to Step 10

Go to Step 11

9

Test the high circuit of the VSS assembly for a short 
to ground. 
Refer to Testing for Short to Ground and extxref 
document="029_body-21" filetype="sgml" 
extrefid="i162420">Wiring Repairs in Wiring 

-

-

 

2004 Hummer H2 

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

 

Systems. 
Did you find and correct the condition?

Go to Step 15

10

1. Test the high circuit of the VSS assembly for 

an open.  

2. Test the low circuit of the VSS assembly for an 

open. 

Refer to Testing for Continuity and extxref 
document="029_body-21" filetype="sgml" 
extrefid="i162420">Wiring Repairs in Wiring 
Systems. 

Did you find and correct the condition?

-

Go to Step 15

-

11

Test the high circuit and the low circuit of the VSS 
assembly for a short together. 
Refer to Circuit Testing and extxref 
document="029_body-21" filetype="sgml" 
extrefid="i162420"> Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

-

Go to Step 15

-

12

1. Remove the VSS assembly.  

2. Inspect the output shaft speed sensor rotor for 

damage or misalignment.  

3. Inspect the case extension bushing for wear.  

Did you find and correct the condition?

-

Go to Step 15

Go to Step 13

13

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

IMPORTANT:

For vehicles equipped with an active transfer 
case, identify the VSS assembly before replacing. 
There are two transfer case speed sensors located 
near the VSS assembly. Refer to the wire colors 
on the schematic to identify the VSS assembly.

-

Go to Step 15

-

14

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

-

Go to Step 15

-

Perform the following procedure in order to verify 
the repair: 

1. Select DTC.  

 

2004 Hummer H2 

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2

 

DTC P0706 

15

2. Select Clear Info.  

3. Operate the vehicle, ensuring that the 

transmission output speed drop is less than 500 
RPM for 2 seconds and output speed is greater 
than 500 RPM for 2 seconds.  

4. Select Specific DTC. 

Enter DTC P0503. 

 
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 in 

Engine Controls 

- 6.0L (LQ4)

System OK

 

2004 Hummer H2 

2004 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E Diagnosis (DTC P0218 To DTC P2771) - Hummer H2