Hummer H2. Manual - part 2470

DTC P0502 

Transmission Oil Cooler Flushing 
and Flow Test (J 35944-A) . 

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Test for correct line pressure. 
Refer to Line Pressure Check Procedure .
Did you find and correct the condition?

-

Go to Step 6

Go to Step 5

5

Test the torque converter stator. 
Refer to Torque Converter Diagnosis 
Procedure . 
Did you find and correct the condition?

-

Go to Step 6

Go to Diagnostic Aids

6

Perform the following procedure in order to 
verify the repair: 

1. Install a scan tool.  

2. Select DTC.  

3. Select Clear Info.  

4. Start and idle the engine until it 

reaches normal operating temperature. 

5. Monitor Engine Run Time and Trans. 

Fluid Temp. on the scan tool.  

6. Drive the vehicle for 10 minutes.  

7. Ensure that the transmission fluid 

temperature has stabilized and is less 
than 129°C (264°F).  

8. Select Specific DTC.  

9. Enter DTC P0218.  

 
Has the test run and passed?

-

Go to Step 7

Go to Step 2

7

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

 

Fig. 2: Vehicle Speed Sensor (VSS) Assembly Diagram 
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 an AC voltage as rotor teeth on 
the output shaft of the transfer case pass through the sensor's magnetic field. The AC voltage level and the 
number of pulses increase as the speed of the vehicle increases. The PCM converts the pulsing voltage to 
vehicle speed. The PCM uses the vehicle speed signal to determine shift timing and torque converter clutch 
(TCC) scheduling. 

When the PCM detects a low vehicle speed when there is a high engine speed in a drive gear range, then DTC 

 

2004 Hummer H2 

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

 

P0502 sets. DTC P0502 is a type B DTC. 

Conditions for Running the DTC 

z

No MAP sensor DTCs P0107 or P0108.  

z

No TP sensor DTCs P0122 or P0123.  

z

No TFP manual valve position switch DTC P1810.  

z

The engine torque is 54-542 N.m (40-400 lb ft).  

z

The TP angle is greater than 12 percent.  

z

The engine speed is greater than 3,000 RPM.  

z

The transmission is not in PARK or NEUTRAL.  

Conditions for Setting the DTC 

The transmission output speed is less than 150 RPM for 3 seconds. 

Action Taken When the DTC Sets 

z

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

z

The PCM commands second gear only.  

z

The PCM commands maximum line pressure.  

z

The PCM inhibits TCC engagement.  

z

The PCM freezes transmission adapt functions.  

z

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.  

z

The PCM stores DTC P0502 in PCM history during the second consecutive trip in which the Conditions 
for Setting the DTC are met.  

Conditions for Clearing the MIL/DTC 

z

The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and 
passes.  

z

A scan tool can clear the MIL/DTC.  

z

The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an 
emission-related diagnostic fault occurring.  

z

The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is 
OFF long enough in order to power down the PCM.  

Test Description 

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

 

2004 Hummer H2 

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

 

3: This step tests the VSS assembly circuit.  

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

DTC P0502 

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 any drive range.  

With the drive wheels rotating, does the scan tool 
Transmission OSS increase with the drive wheel 
speed?

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.

-

Go to Intermittent 

Conditions in 

Engine Controls - 

6.0L (LQ4)

Go to Step 3

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

Does the resistance measure within the specified 
range?

976-

2354 

ohm

Go to Step 4

Go to Step 7

1. Place the transmission in NEUTRAL.  

2. Select AC volts.  

 

2004 Hummer H2 

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