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No Response From TCM - NAG1

NO RESPONSE FROM TCM - NAG1


No Response From TCM - NAG1:





POSSIBLE CAUSES
- (Z912) ground circuit open
- (F942) fused transmission relay output circuit open or short
- (D65) CAN C BUS (+) circuit open
- (D64) CAN C BUS (-) circuit open
- Transmission control module

DIAGNOSTIC TEST

1. TEST FOR INTERMITTENT CONDITION
Turn the ignition on.

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.

With the scan tool, select ECU view.

NOTE:
- A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.
- Check the FCM for any active CAN C hardware and any ignition related DTCs, perform DTCs before proceeding.

Q: Does the scan tool display a red X next to the module?

YES: Go To 2
NO: he no response condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent , pushed out, and corroded terminals.

2. (Z912) GROUND CIRCUIT OPEN




Turn the ignition off.
Disconnect the Transmission Control Module C1 harness connector.
Using a 12-volt test light connected to 12-volts, check the (Z912) ground circuit.

Q: Does the test light illuminate brightly?

YES: Go To 3
NO: Repair the (Z912) ground circuit for an open.
Perform NAG1 TRANSMISSION VERIFICATION TEST -VER 1. Transmission Verification Test

3. (F942) FUSED TRANSMISSION RELAY OUTPUT CIRCUIT OPEN OR SHORTED




Turn the ignition on.
Using a 12-volt test light connected to ground, check the (F942) Fused Transmission Relay Output circuit.

Q: Does the test light illuminate brightly?

YES: Go To 4
NO: Repair the (F942) Fused Transmission Relay Output circuit for an open or short.
Perform NAG1 TRANSMISSION VERIFICATION TEST -VER 1. Transmission Verification Test

4. (D65) CAN C BUS (+) CIRCUIT OPEN




Turn the ignition off.
Disconnect the FCM C1 harness connector.
Disconnect the TCM C2 harness connector.
Measure the resistance of the (D65) CAN C Bus (+) circuit between the FCM connector and the TCM connector.

Q: Is resistance below 5.0 ohms?

YES: Go To 5
NO: Repair the (D65) CAN C Bus (+) circuit for an open.
Perform NAG1 TRANSMISSION VERIFICATION TEST VER 1. Transmission Verification Test

5. (D64) CAN C BUS (-) CIRCUIT OPEN




Measure the resistance of the (D64) CAN C Bus (-) circuit between the FCM connector and the TCM connector.

Q: Is resistance below 5.0 ohms?

YES: Replace the Transmission Control Module.
Perform NAG1 TRANSMISSION VERIFICATION TEST -VER 1. Transmission Verification Test
NO: Repair the (D64) CAN C Bus (-) circuit for an open.
Perform NAG1 TRANSMISSION VERIFICATION TEST -VER 1. Transmission Verification Test