Solenoid Supply/Watchdog
P0702 - SOLENOID SUPPLY/WATCHDOG
When Monitored and Set Condition
- When Monitored: Always monitored with system active at each ignition cycle.
- Set Condition: During the power up of the TCM, it tests the ability of the external watchdog to shut down the Solenoid Supply Voltage driver.
For a complete Transmission Control Module Circuit Diagram, [1][2]Automatic Transmission/Transaxle.
Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT
NOTE: Low fluid level can be the cause of many transmission problems. If the fluid level is low, locate and repair the leak then check and adjust the fluid level.
NOTE: Always perform diagnostics with a fully charged battery to avoid false symptoms.
With the scan tool, read Engine DTCs. Check and repair all engine DTCs prior to performing transmission symptom diagnostics.
With the scan tool, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Most DTCs set on start up but some must be set by driving the vehicle such that all diagnostic monitors have run.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.
Continue
Go To 2
2. SOLENOID DTCS PRESENT
With the ignition on.
With the scan tool, read Transmission DTCs.
Are any Solenoid DTCs present?
Yes
- Repair all Solenoid DTCs before proceeding with test.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test
No
- Go To 3
3. MEASURE SOLENOID CONTROL CIRCUIT VOLTAGES
Turn the ignition off.
Disconnect the Transmission Solenoid Assembly harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of each of the Solenoid Control circuits in the Transmission Solenoid Assembly harness connector.
Is the voltage below 1.0 volt for each measurement?
Yes
- Go To 4
No
- Go To 6
4. CHECK FOR A SHORTED SOLENOID
Turn the ignition off.
Reconnect the Transmission Solenoid Assembly harness connector.
Disconnect the TCM C2 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance from the Solenoid Voltage Supply circuit to each of the Solenoid Control circuits in the TCM C2 harness connector.
NOTE: The resistances of the Solenoids should be:
Modulation Pressure Solenoid - 2.5 - 6.5 ohms
Shift Solenoid - 4.0 - 8.0 ohms
TCC Solenoid - 2.0 - 4.0 ohms
1-2/4-5 Solenoid - 2.5 - 6.5 ohms
2-3 Solenoid - 2.5 - 6.5 ohms
3-4 Solenoid - 2.5 - 6.5 ohms
Is the resistance of each of the Solenoids within specification?
Yes
- Replace the Solenoid that measured below specification. Removal.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test
No
- Go To 5
5. SOLENOID SUPPLY VOLTAGE CIRCUIT SHORT TO ANOTHER CIRCUIT
Turn the ignition off.
Disconnect the Transmission Solenoid Assembly harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance from the Solenoid Supply Voltage circuit to all other circuits in the Transmission Solenoid Assembly harness connector.
Is the resistance above 100 kohms for all measurements?
Yes
- Replace the Transmission Control Module. Transmission Control Module - Removal.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test
No
- Repair the Solenoid Supply Voltage circuit for a short to other circuit(s).
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test
6. SOLENOID CONTROL CIRCUIT SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the TCM C2 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage of each of the Solenoid Control circuits in the Transmission Solenoid Assembly harness connector.
Is the voltage below 1.0 volt for each measurement?
Yes
- Replace the Transmission Control Module. Transmission Control Module - Removal.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test
No
- Repair the Solenoid Control circuit that measured above 1.0 volt for a short to voltage.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test