Drive Authorization System Communication Error With EIS (CGW)

1630 DRIVE AUTHORIZATION SYSTEM COMMUNICATION ERROR WITH EIS (CGW)

For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

Ignition on.

- Set Condition:

The ECM lost communication over the CAN Bus circuit with the EIS. The circuit is continuously monitored.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Refer to Testing for diagnostic procedures and for further possible causes.

Diagnostic Test

1. ACTIVE DTC

NOTE: Review the vehicle repair history. If the Electronic Ignition Switch/Central Gateway Module has been replaced, ensure the that it has been programmed correctly.

Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 3

No

- Go To 2

2. INTERMITTENT CONDITION

NOTE: Check for any of the follow conditions:
- Poor wire to terminal connection
- Corroded terminals
- Backed out or loose terminals
- Broken wire internal to the insulation
- Dirty (partial) module ground

Were any of the above condition present?

Yes

- Repair as necessary.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No

DTC is not active at this time. Test complete.

3. OTHER COMMUNICATION DTC(S)

Using the scan tool, check other CAN C modules.

Are communication DTC(s) present?

Yes

- Refer to Testing

No

- Go To 4

4. MEASURE VOLTAGE AT TPM MODULE

Turn the ignition on.

Gain access to the ECM harness connector, but do not disconnect.

Backprobe and measure the voltage on both the CAN C Bus (+) and the CAN C (-) circuits.

NOTE: With the BUS active, the voltmeter should read, CAN C Bus (-) 1.59 volts and CAN C Bus (+) 2.55 volts. The voltage will fluctuate due to communication.

Does the voltmeter read the correct voltages?

Yes

- Replace the ECM.
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No - CAN C Bus (-)

- Repair the open in the CAN C Bus (-).
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test

No - CAN C Bus (+)

- Repair the open in the CAN C Bus (+)
- Perform TPM VERIFICATION TEST. Tire Pressure Monitor (TPM) Verification Test