Normal Operation

Safing sensor output circuit shorted to battery voltage.

Normal Operation

The diagnostic module measures the voltage at pin 2-5 (airbag module feed) and 2-6 (safing sensor output monitor) at the diagnostic module connector. The voltage at these pins is dependent on charging system voltage as shown in the table below. If the voltage at either pin exceeds 5 volts, a fault code 22 will be generated.

Possible Causes

• A short between pins 2-5 or 2-6 and another wire. (The wiring to the safing sensor carries voltages above 5 volts).
• A short between the cable reel cassette circuit and other 12 volt circuits at the steering column head.
• A short across the normally open contacts of the safing sensor.
• Vehicle charging system voltage too high. If the generator output is greater than 17V, fault code 22 may be logged.

Fault Analysis

WARNING: Read and adhere to all warnings and safety procedures at the start of this section when working on the airbag system.

1. Disarm the airbag system and fit airbag simulators (6.4.21.4).
2. Check the voltage at the battery with the engine running at approximately 1500 rpm.
   If the voltage is 14.8 ±0.5 volts, the charging voltage is within specification, go to step 3.
   If the voltage is significantly above 14.8 volts (the voltage regulator set point) service the charging system. Clear the code 22. Rearm the airbags (6.4.21.4)
3. Check in the area of the diagnostic module connector for harness damage which could cause a short circuit to 12 volts. (Note: The airbag system harness runs are sheathed in black plastic protection and harness damage is unlikely.)
   If no harness damage is evident, go to step 4.
   If harness damage is identified, service the wiring as necessary. Clear the code 22. Rearm the airbags (6.4.21.4).
4. Switch on the ignition. Monitor the voltage at pins 2-5 and 2-6 whilst rotating the steering from lock to lock in both directions.
   If the voltage at both pins remains below 5.0 volts, go to step 5.
   If the voltage rises to above 5.0 volts, service the cable reel cassette or wiring as necessary. Clear the code 22. Rearm the airbags (6.4.21.4).
5. With the ignition on, check the voltage at pins 2-5 and 2-6 whilst manipulating the bulkhead and safing sensor harnesses.
   If the voltage rises above 5.0 volts, service the wiring fault in the harness area being manipulated at the time the voltage rise occurred.
   If no voltage rise occurs, fit a new safing sensor as the most likely cause of the code 22. Clear the code 22 and rearm the airbags (6.4.21.4).