I033

CIRCUIT DESCRIPTION


Code I033 will set if the ignition is on and the IPC is not able to exchange data with the Diagnostic Energy Reserve Module (DERM) (Supplemental Inflatable Restraint (SIR) controller). If any other communication codes are stored along with I033, see the chart "Multiple Intermittent Codes." When this is the only communication code stored, the problem must be one of the following:

^ An open in CKT 800 between IPC and DERM and a second open between DERM and ACP

^ An open in CKT 1139 or CKT 1731

^ A faulty DERM

During the time the failure is present, the IPC will display the Service Supplemental Restraints message.

TEST DESCRIPTION

Test numbers refer to circled numbers on the diagnostic chart.

1. Normal operation is for the DERM to flash the Inflatable Restraint telltale 7 times at key "on." If this does not happen SIR system diagnosis is required.

2. Disconnecting the 2-way connector disables the SIR system for diagnosis. Cavity "A11" (DeVille/Concours) or "B11" (Eldorado/Seville) is the serial data line to the IPC. Under normal operation the voltage on this line will appear as 3 to 5 volts and be constantly fluctuating. If this is not the case, the most likely cause is an open in CKT 800 between the IPC and the DERM.

3. Voltage across these terminals indicates the DERM was receiving good power and ground.

4. Before replacing the DERM, it is important to ensure no connector damage or loose terminals are causing intermittent contacts.

5. The DERM power or ground is now suspected. This step determines if the power circuit is good by comparing it to a known good ground.

NOTES ON INTERMITTENTS

If only Code I033 is stored as "History", check the DERM power (Cavities A9," "A16"), grounds (Cavities "A1," A12"), and serial data (Cavities "A11," "B11") for intermittent open circuits.