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P1501-VEHICLE SPEED SENSOR 1/2 CORRELATION - DRIVE WHEELS
For a complete wiring diagramRefer to Section 8W.
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P1502-VEHICLE SPEED SENSOR 1/2 CORRELATION - NON DRIVE WHEELS
For a complete wiring diagramRefer to Section 8W.
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When Monitored:
Ignition on.
Set Condition:
S/C Switch No.1 is mechanically stuck in the On/Off, Resume/Accel, or Set position for too long. One trip fault.
Possible Causes
(V37) S/C SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(V37) S/C SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND OPEN
(V37) S/C SIGNAL CIRCUIT SHORTED TO GROUND
(V37) S/C SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND
SPEED CONTROL SWITCH
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.SPEED CONTROL SWITCH STATUS
Start the engine.
With a scan tool, monitor each which function for the Speed Control Switches.
Press and release each Speed Control Button.
- Resume/Accel
-Cancel
- Decel (Coast)
-On/Off
-Set
Does each switch function change status when pressing each switch?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.SPEED CONTROL SWITCHES
Turn the ignition off.
Disconnect and remove the Speed Control Switches from the steering wheel per Service Information.
Measure the resistance across each Speed Control Switch.
Monitor the ohmmeter while pressing each function button on each switch.
Resume/Accel - 15.4 kohms
Cancel - 1.24 kohms
Coast - 2.94 kohms
On/Off -0.47 kohms
Set - 5.49 kohms
Does the function on the Speed Control Switches have the correct resistance value?
Ye s>>
Go To 3
No>>
Replace the Speed Control Switch that had the incorrect resistance value.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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5.(K900) SENSOR GROUND CIRCUIT OPEN
NOTE: The measurement must be taken from both Speed Control
Switch harness connectors.
Measure the resistance of the (K900) Sensor ground circuit from the
Speed Control harness connector to the appropriate terminal of special
tool #8815.
Is the resistance below 5.0 ohms for both measurements?
Ye s>>
Go To 6
No>>
Repair the open in the (K900) Sensor ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
6.(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (V37) S/C Switch No.1
Signal circuit in the Speed Control harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (V37) S/C Switch No.1
Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 7
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7.(V37) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (V37) S/C Switch No.1 Signal cir-
cuit and the (K900) Sensor ground circuit in the Speed Control harness
connector.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the short between the (V37) S/C Switch No.1 Signal
circuit and the (K900) Sensor ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 8
8.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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P1618-SENSOR REFERENCE VOLTAGE 1 CIRCUIT ERRATIC
For a complete wiring diagramRefer to Section 8W.
Page 150 of 5267

When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes the Primary 5-volt Supply circuit voltage is varying too much too quickly. One Trip
Fault. ETC light is flashing.
Possible Causes
(F855) PRIMARY 5-VOLT SUPPLY SHORTED TO GROUND
(F855) PRIMARY 5-VOLT SUPPLY SHORTED TO BATTERY VOLTAGE
(F855) PRIMARY 5-VOLT SUPPLY CIRCUIT OPEN
5-VOLT SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(F855) PRIMARY 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Disconnect all the Sensors that share the (F855) Primary 5-volt Supply
circuit.
NOTE: This code can be caused by the improper installation of
after market accessories that may be causing excessive noise on
the (F855) 5-volt Supply circuit.
Measure the resistance between ground and the (F855) Primary 5-volt
Supply circuit in the CKP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) Primary 5-volt Sup-
ply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
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3.SENSOR SHORTED TO GROUND
Connect the C2 PCM harness connector and all the previously discon-
nected Sensor except for the CKP Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) Primary 5-volt Supply circuit at the
Throttle Body harness connector.
CAUTION: You must Turn the Ignition Off when disconnecting any
of the Sensor harness connectors and Turn the Ignition On to
check the voltage readings.
While monitoring the voltage, disconnect each Sensor harness connec-
tor that shares the (F855) Primary 5-volt Supply circuit, one at a time.
Does the voltage increase above 4.5 volts when disconnecting
any of the Sensor harness connectors?
Ye s>>
Replace the Sensor that causes the (F855) Primary 5-volt
Supply circuit voltage to increase when disconnected.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.5-VOLT SENSOR
Turn the ignition off.
Connect all the previously disconnected Sensors except for the CKP
Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) Primary 5-volt Supply circuit at the
CKP Sensor harness connector.
Is the voltage between 4.8 and 5.2 volts?
Ye s>>
Replace the Crank Position Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5