Modules that are connected to the shared communication circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have pre-recorded information about what messages are needed to be exchanged on the serial data circuits for each virtual network. The messages are usually supervised and some periodic messages are used by the receiver module as an availability indication of the transmitter module.
This diagnostic procedure supports the following DTC:
DTC U0167 Lost Communication With Theft Deterrent Control Module
• | The ignition is ON and the engine is cranking. |
• | The DTC U0167 diagnostic runs once per drive cycle. |
The ECM cannot communicate with the theft deterrent control module
• | The DTC U0167 is stored in the ECM. |
• | Engine control system functions are disabled and the engine will not start. |
• | A current DTC clears when the malfunction is no longer present. |
• | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction. |
• | The scan tool can clear the DTC from the module memory. |
• | An open or a short in the serial data circuits of the theft deterrent control module can cause a DTC U0167 to set. The serial data circuit fault will also cause the following conditions: |
- | The theft deterrent status will switch to Enable and the engine will crank but not start. |
- | If there is open circuit, the scan tool will not communicate with the ECM, but will continue to communicate with the TCM. |
- | If there is a short circuit, the scan tool will not communicate with either the ECM or the TCM. |
- | The DTC U0167 will be stored in memory and is displayed by the scan tool when communication with the ECM resumes. |
• | An intermittent electrical condition in the theft deterrent system can cause this code to set. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
The numbers below refer to the step numbers in the diagnostic table.
This step tests for ignition voltage to the theft deterrent module. The theft deterrent module cannot communicate with the ECM if there is no ignition positive voltage.
This step tests for a good ground to the theft deterrent module. The theft deterrent module cannot communicate with the ECM if there is no ground circuit.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Theft Deterrent System Schematics Connector End View Reference: Theft Deterrent System Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Theft Deterrent? | Go to Step 2 | |
2 | Is DTC U0167 present? | Go to Step 3 | |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 6 | |
Connect a test lamp to B+ and the ground circuit of the theft deterrent module. Did the test lamp illuminate? | Go to Step 7 | Go to Step 5 | |
5 | Repair the open or the poor connection in the theft deterrent module ground circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | Go to Step 10 | Go to Step 7 |
6 | Repair the open or the poor connection Ignition 1 voltage circuit of the theft deterrent module. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | Go to Step 10 | Go to Step 7 |
7 | Inspect for a poor electrical connection at the theft deterrent control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct a condition? | Go to Step 10 | Go to Step 8 |
8 |
Did the engine start and run with no DTC U0167 set? | Go to Diagnostic Aids | Go to Step 9 |
9 | Replace the theft deterrent control module. Refer to Theft Deterrent Module Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 |
Did DTC U0167 set? | Go to Step 2 | System OK |