Astra L4-1.8L (2009)
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
LS GMLAN initial test
1. Ignition OFF, disconnect the X1 harness connector at the steering column control module (SCCM).
2. Ignition ON, test for less than 1.0 volt between the low speed GMLAN serial data circuit of the DLC and ground.
‹› If greater than the specified range, test the serial data circuit for a short to voltage.
3. Test for infinite resistance between the serial data circuit of the DLC and ground.
‹› If less than infinite resistance, test the serial data circuit for a short to ground.
4. Test for less than 1.0 ohm in the serial data circuit between the DLC and the SCCM.
‹› If greater than the specified range, test the serial data circuit for an open/high resistance.
5. Disconnect the X1 harness connector at the SDM, install a 3A fused jumper wire from the SDM terminal 35 to the harness side of X1.
6. With a scan tool, attempt to communicate with the IPC.
‹› If communication is established, refer to Diagnostic 2.
‹› If communication is not established, refer to Diagnostic 1.
LS GMLAN test 1
1. Remove the jumper wire from the SDM.
2. Disconnect the following harness connectors for the following modules.
*
REC X5
*
UEC X2
*
IPC X1
*
SCCM X1
3. Test each serial data circuit of the disconnected modules for a short to voltage or a short to ground, with the modules disconnected. If the circuit
tests normal, install each module one at a time in the following order, while attempting to communicate after each module is connected until
communications stop.
*
SCCM X1
*
IPC X1
*
UEC X2
*
REC X5
4. Replace the last module connected that caused communication to stop.
LS GMLAN test 2
1. Remove the jumper wire from the SDM.
2. Install a 3A fused jumper wire between terminal 37 and 38 on the harness side of the SDM X1 harness connector.
3. Attempt to communicate with the AHS, communication should not be available.
‹› If communication is established, replace the SDM.
4. Disconnect the jumper wire for the harness side of the SDM X1 harness connector.
5. Disconnect the following harness connectors of the following modules.
*
Auxiliary HVAC Module X1
*
TPM X1
*
Infotainment display unit X1
*
SCCM X1
6. Test each serial data circuit of the disconnected modules for a short to voltage or a short to ground, with the modules disconnected. If the circuit
tests normal, install each module one at a time in the following order, while attempting to communicate after each module is connected until
communications stop.
*
SCCM X1
*
Infotainment display unit X1
