Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 1872
P0642-SENSOR REFERENCE VOLTAGE 1 CIRCUIT LOW
For a complete wiring diagram Refer to Section 8W
21 - 22
AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS
LX
Theory of Operation
The Sensor Supply Voltage circuit supplies a 6-volt power supply to the two input speed sensors. The Sensor Sup-
ply Voltage circuit is constantly monitored for correct voltage between 4.8 to 7.2 volts. If the voltage does not stay
within the 4.8 to 7.2 volt range, the appropriate DTC will set.
•
When Monitored:
Continuously with the ignition on and no undervoltage condition exist.
•
Set Condition:
When the monitored sensor voltage is not within specified limits drops below 4.8 volts.
Possible Causes
SPEED SENSOR DTCS PRESENT
(T72) SENSOR SUPPLY VOLTAGE SHORT TO GROUND
INTERNAL SHORT IN THE ELECTROHYDRAULIC CONTROL UNIT ASSEMBLY
TRANSMISSION CONTROL MODULE
Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
Diagnostic Test
1.
CHECK FOR SPEED SENSOR DTCS
With the scan tool, check for other transmission DTCs.
Are there any speed sensor DTCs present?
Yes
>> Refer to the Transmission category and perform the appropriate symptom(s). (Refer to 21 - TRANS-
MISSION/TRANSAXLE/AUTOMATIC - NAG1 - DIAGNOSIS AND TESTING)
No
>> Go To 2
2.
CHECK FOR (T72) SENSOR SUPPLY VOLTAGE SHORT TO GROUND
Turn the ignition off to the lock position.
Disconnect the Electrohydraulic Control Unit Assembly harness connec-
tor.
Disconnect the TCM C2 harness connectors.
Measure the resistance between ground and the (T72) Sensor Supply
Voltage circuit in the TCM harness connector.
Is the resistance below 5.0 ohms?
Yes
>> Repair the (T72) Sensor Supply Voltage circuit for a short
to ground
Perform NAG1 TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - NAG1 - STANDARD PROCEDURE)
No
>> Go To 3
LX
AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS
21 - 23
3.
CHECK FOR A SHORT IN THE ELECTOHYDRAULIC CONTROL UNIT
Reconnect the Electrohydraulic Control Unit Assembly harness connec-
tor.
Measure the resistance between ground and the (T72) Sensor Supply
Voltage circuit in the TCM harness connector.
Is the resistance below 5.0 ohms?
Yes
>> Repair the Electrohydraulic Control Unit Assembly for a
short to ground. Refer to 21- AUTOMATIC TRANSMIS-
SION-AUTOMATIC
TRANSMISSION
NAG1/SERVICE
INFORMATION for proper service procedures.
Perform NAG1 TRANSMISSION VERIFICATION TEST -
VER 1. (Refer to 21 - TRANSMISSION/TRANSAXLE/AU-
TOMATIC - NAG1 - STANDARD PROCEDURE)
No
>> Using the schematics as a guide, check the Transmission
Control Module (TCM) terminals for corrosion, damage, or
terminal push out. Pay particular attention to all power and
ground circuits. If no problems are found, replace the TCM
per the Service Information. (Refer to 8 - ELECTRICAL/
ELECTRONIC
CONTROL
MODULES/TRANSMISSION
CONTROL MODULE - DESCRIPTION)
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. (Refer to 21 - TRANSMISSION/
TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
21 - 24
AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS
LX
P0643-SENSOR REFERENCE VOLTAGE 1 CIRCUIT HIGH
For a complete wiring diagram Refer to Section 8W
LX
AUTOMATIC TRANSMISSION NAG1 - ELECTRICAL DIAGNOSTICS
21 - 25
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст