Electrical Troubleshooting
Troubleshooting Flowchart — Vehicle Speed Sensor (VSS)
• OBD II Scan Tool indicates Code
P0501.
• Self-diagnosis indicator light
blinks four times.
Possible Cause
• Disconnected vehicle speed
sensor (VSS) connector
• Short or open in VSS wire
• Faulty VSS
Check that the speedometer oper-
ates correctly.
Does the speedometer operate?
Refer to
section 23
for vehicle
speed sensor (VSS) test.
YES
• Make sure lifts, jacks and safety stands are placed properly (see
section 1
).
• Set the parking brake securely, and block the rear wheels.
• Jack up the front of the vehicle, and support it with safety stands.
Does O V and approx. 5 V or more
appear alternately?
YES
Check for open in the wire
between the B13 terminal and
the vehicle speed sensor (VSS). If
wire is OK, check the VSS (see
section 23
).
Check for loose PCM connectors.
If necessary, substitute a known-
good PCM and recheck.
Check the VSS Voltage:
1. Turn the ignition switch OFF.
2. Raise the vehicle.
3. Shift the transmission to
position.
4. Disconnect the A (26P) and B
(16P) connectors from the
PCM.
5. Turn the ignition switch ON (II).
6. Rotate the front wheel and
check for the voltage between
the B13 and A26 terminals.
NOTE: Block the other wheel
so it does not turn or you will
get incorrect test results.
Main Menu
Table of Contents