SIR Diagnostic System Check

SIR Diagnostic System Check:

DESCRIPTION:

When the ignition switch is first turned "ON" (Run or Bulb Test), system voltage is applied from fuse # 18 to the DERM at the "Ignition 1" input terminals A3 and B3 and from fuse #16 to the DERM at the "SIR Indicator High" input. The DERM responds by flashing the "INFL REST" warning lamp 7 to 9 times. When the engine is being cranked, system voltage is applied from fuse #1 to the DERM at the "Crank" input. The DERM responds by grounding the "SIR Indicator Low" output until system voltage is removed from the "Crank" input. This results in the "INFL REST" warning lamp being "ON" steady during cranking. After cranking, the DERM will again flash the "INFL REST" warning lamp 7 to 9 times.

NOTES ON SYSTEM CHECK CHART:

1. The "INFL REST" warning lamp should flash 7 to 9 times after ignition is first turned "ON".

2. The "INFL REST" warning lamp should remain "ON" steady during cranking.

3. Improper operation of the "INFL REST" warning lamp is indicated. This test differentiates a warning lamp stays "ON" condition from a warning lamp does not come "ON" condition.

4. After cranking, the "INFL REST" warning lamp should flash 7 to 9 times then go "OFF".

5. The "INFL REST" warning lamp has successfully completed the "Bulb Check". No current codes exist.

6. The "INFL REST" has completed a "Bulb Check" and indicates current codes exist.

DIAGNOSTIC AIDS:

The order in which codes are diagnosed is very important. Failure to diagnose the codes in the order specified may result in extended diagnostic time, incorrect diagnosis, and incorrect parts replacement.