Chart A History Code Diagnosis

CIRCUIT DESCRIPTION

When system voltage is applied to the DERM, it will perform the "Turn-ON Tests" followed by the "Continuous Monitoring Tests." If no faults are detected, the DERM will perform the "Steering Column Resistance Test." When a fault is detected, the DERM will store a current DTC and illuminate the "INFL REST" indicator. The DERM will clear current DTCs and store them as history DTCs when the fault is no longer detected or when the ignition switch is cycled, except for Current DTC 51. Current DTC 51 can only be cleared with the TK00000 TECH 1 modular diagnostic system and will then be stored as History DTC 51. History DTC 51 can be cleared for the current ignition cycle, but will reappear at the next ignition cycle.

TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. The DERM has detected an event in which the "Sense High" input voltage was a certain percentage or more of deployment loop voltage and, simultaneously, the "Sense Low" voltage was a certain percentage or less of deployment loop voltage.
2. Checks for intermittent conditions within the steering column.
3. Checks for intermittent conditions in the "36 VLR" CKT 236.
4. Checks for an open Fuse C-22 or "INFL REST" indicator, or an uncleared DTC 61 after a wiring repair in CKT 39 was completed. Also checks for intermittent faults in CKTs 688 and 358.
5. Checks for intermittent opens in the ground path of the deployment loop between the base of the steering column and both discriminating sensors.
6. Checks for intermittent wiring shorts between the "36 VLR" CKT 236 and CKTs 340, 341, 347" 348 or 349 of the SIR circuit.
7. Checks for intermittent shorts to B+ in the "36 VLR" CKT 236.
8. Checks for intermittent shorts to ground in the "36 VLR" CKT 236.
9. Checks for intermittent opens in the "36 VLR" CKT 236.
10. Checks for intermittent opens in the "Force High" CKT 714 and the "Force Low" CKT 688.
11. Checks for intermittent opens or shorts to ground in the "Sense Low" CKT 752.
12. Checks for shorts to B+ or ground in CKTs 347, 348, 349, 688, 714, 752 or 753.
13. Checks for shorts between the "36 VLR" CKT 236 and CKTs 347, 348 and 349.
14. Checks for intermittent opens in the "36 VLR" CKT 236.
15. Checks for intermittent opens between Fuse C-23 and the arming sensor (CKT 1139B).