Engine CAN Message Missing

(P0600) ENGINE CAN MESSAGE MISSING





When Monitored and Set Condition
- When Monitored: CAN Bus Circuit error not present 1 second after ignition on and not in Park or Neutral, no System Overvoltage or System Undervoltage conditions present, or transmission in Park or Neutral and engine RPM greater than 850 RPM.
- Set Condition: This DTC is set if a CAN ID was not received in the required time, from the Powertrain Controller.

POSSIBLE CAUSES
- CAN BUS CIRCUIT DTC PRESENT
- ENGINE DTCS PRESENT
- CAN C BUS +/- CIRCUIT OPEN
- POWERTRAIN CONTROL MODULE
- TRANSMISSION CONTROL MODULE

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 in accordance with the Service Information.

Note: Always perform diagnostics with a fully charged battery to avoid false symptoms.
With the DRB III*, read the engine DTCs. Check and repair all engine DTCs prior to performing transmission symptom diagnostics.
With the DRB III*, 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: Verify flash level of transmission controller. Some problems are corrected by software upgrades to the transmission controller.

Note: Check for any Technical Service Bulletins that may apply.

Perform this procedure prior to Symptom diagnosis.
Continue
Go To 2

2. (P0720) CAN BUS CIRCUIT DTC PRESENT





Turn the ignition on.
With the DRB III*, read Transmission DTCs.

Note: If DTC (P0720) CAN BUS CIRCUIT is present, perform diagnostics on that symptom first.

Is DTC (P0720) CAN BUS CIRCUIT present?
Yes>>Refer to the Transmission - Electrical Diagnostics category and perform the appropriate symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST.
No>>Go To 3

3. CHECK TO SEE IF ENGINE DTCS ARE PRESENT





With the ignition on.
With the DRB III*, read Engine DTCs.
Are any performance or bus related Engine DTCs present?
Yes>>Refer to the Engine - Electrical Diagnostics category and perform the appropriate symptom.
Perform NAG1 TRANSMISSION VERIFICATION TEST.
No>>Go To 4

4. CAN C BUS +/- CIRCUIT OPEN





Turn the ignition off.
Disconnect the PCM C4 harness connector.
Disconnect the TCM C3 harness connector.

Note: Check connectors - Clean/repair as necessary.

Measure the resistance of the CAN C Bus (+) circuit from the PCM C4 harness connector to the TCM C3 harness connector.
Measure the resistance of the CAN C Bus (-) circuit from the PCM C4 harness connector to the TCM C3 harness connector.
Is the resistance above 5.0 ohms on either circuit?
Yes>>Repair the faulty CAN C Bus circuit for an open.
Perform NAG1 TRANSMISSION VERIFICATION TEST.
No>>Go To 5

5. PCM - ENGINE CAN MESSAGE MISSING





With the ignition off.
Reconnect the TCM C3 harness connector.
Replace and program the Powertrain Control Module.
With the DRB III*, erase Transmission DTCs.
Start the engine.
With the brakes firmly applied, shift the gear selector into Drive.
With the DRB III*, read Transmission DTCs.
Did DTC (P0600) ENGINE CAN MESSAGE MISSING set again?
Yes>>Replace the Transmission Control Module in accordance with the Service Information.
Perform NAG1 TRANSMISSION VERIFICATION TEST. Verification Tests
No>>Test Complete.