Accepted Answer

The vehicle speed comes from the ABS controller by averaging the two axles speeds and sends it to the communication network. The engine controller picks up the signal and provides you with the speed. You have to be able to talk or interrogate the ABS controller to see if there is a problem within the brake system. The next step is to look in the engine controller for the speed signal from the ABS. If you are using a scan tool that can talk to the abs and abs is unresponsive than you may need a work with the ABS.

 

here are the diagnostic steps

 

P0500-NO VEHICLE SPEED SENSOR SIGNAL

When Monitored and Set Condition:

P0500-NO VEHICLE SPEED SENSOR SIGNAL

When Monitored: Engine Temperature greater than 104 deg F. , MAP vacuum approximately

159 to 169 inches of mercury and Engine RPM between 1400 and 3000 rpm.

Set Condition: No Vehicle Speed Signal for more than 15 seconds on two consecutive

trips.

POSSIBLE CAUSES

INTERMITTENT CONDITION

VEHICLE SPEED SIGNAL CIRCUIT OPEN

VEHICLE SPEED SIGNAL CIRCUIT SHORTED TO GROUND

VEHICLE SPEED SIGNAL CIRCUIT SHORTED TO VOLTAGE

PCM

TEST ACTION APPLICABILITY

1 Ignition on, engine not running.

With the DRBIIIt, read DTCs.

NOTE: Any VSS DTCs in the CAB Module or Body Controller must be

properly diagnosed before continuing.

Is the Good Trip Counter displayed and equal to zero?

All

Yes ! Go To 2

No ! Go To 6

2 Turn the ignition off.

Disconnect the Powertrain Control Module harness connectors.

Disconnect the ABS Control Module harness connector.

Measure the resistance of the Vehicle Speed Signal circuit between the PCM harness

connector and the ABS Control Module harness connector.

Is the resistance above 5.0 ohms?

All

Yes ! Repair the open Vehicle Speed Signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

No ! Go To 3

3 Turn the ignition off.

Disconnect the Powertrain Control Module harness connectors.

Disconnect the ABS Control Module harness connector.

Measure the resistance between ground and the Vehicle Speed Signal circuit at the

PCM harness connector.

Is the resistance below 100 ohms?

All

Yes ! Repair the short to ground in the Vehicle Speed Signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

 

 

 

TION APPLICABILITY

 

4 Turn the ignition off.

Disconnect the PCM harness connector.

Ignition on, engine not running.

Measure the voltage on the Vehicle Speed Signal circuit at the PCM harness

connector.

Is the voltage above 4.8 volts?

All

Yes ! Repair the short to voltage in the Vehicle Speed Signal circuit.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

No ! Go To 5

5 If there are no possible causes remaining, view repair. All

Repair

Replace and program the PCM in accordance with the Service

Information.

Perform POWERTRAIN VERIFICATION TEST VER - 5.

6 NOTE: The conditions that set the DTC are not present at this time. The

following list may help in identifying the intermittent condition.

WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A

DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE

PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.

 

With the engine running at normal operating temperature, monitor the DRBIIIt

parameters related to the DTC while wiggling the wiring harness. Look for parameter

values to change and/or a DTC to set.

Review the DRBIIIt Freeze Frame information. If possible, try to duplicate the

conditions under which the DTC was set.

Refer to any Technical Service Bulletins (TSB) that may apply.

Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or

partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed

out, or corroded terminals.

Were any of the above conditions present?

All

Yes ! Repair as necessary or refer to the proper ABS Diagnostic Manual

and perform the appropriate symptom diagnostics.

Perform POWERTRAIN VERIFICATION TEST VER - 5.