Component Tests and General Diagnostics
Preliminary work:
Diagnosis - Function Test Function Test - Section 11
Preparation for DTC readout
1. Review sections 11, 12, 13, 20, 22, 31
Section 11, Function Test - Section 11
Section 13, Fault Frequency, Time Span - Section 13
Section 20, Component Locations - Section 20
Section 22, Preparation For Test - Section 22
Section 31, Control Module Programming (Vehicle Equipment) - Section 31
2. Connect Hand-Held Tester (HHT) as per connection diagram, see section 0, and readout DTC memory. Connection and Use of Test Equipment - Section 0
3. Fuses OK,
4. Battery voltage 11 - 14 V.
CAUTION!
Do not connect battery trickle charger.
CAUTION!
Risk of injury when performing Diagnostic Tests and repairs on components of the SRS system and/or the ETR.
Store both airbags and side airbags with opening surface pointing upward. Do not expose to temperatures above 100 °C.
Interrupt any electrical current from reaching the airbag unit.
Review section 11. Function Test - Section 11
NOTE: Diagnostic trouble codes (DTC's) can only be read out and erased using the Hand-Held Tester (HHT).
TIP: When installing additional accessories, observe harness clearances near SRS sensor lines.
Test equipment; See MBNA Standard Service Equipment Program
Hand-Held Tester (HHT) 1) See S.I. in groups 58 and 99.
1) Available through the MBNA Standard Equipment Program.
NOTE:
A current fault is indicated by the DTC being highlighted in black.
Additional detailed information is given with most DTC's, which will indicate possible faults conditions or portions there of:
> ohms Resistance too great.
< ohms Resistance too low.
[] - Short circuit to ground (GND)
[] + Short circuit to positive (POS).
-//- Open circuit.
Fault frequency and time span of the fault can be read by pressing the [i] key.
Fault frequency:
Faults are noted by frequency of occurrence, i.e.: 5 periodic faults, 5 occurances, eliminated 5 times.
Time span:
The amount of time elapsed since last fault, or since fault eliminated itself.
Actual values:
Four displays are possible:
Root (Check mark), F, ON, OFF.
Root: Noted values are within the nominal values.
F : Noted values are outside the nominal values.
ON: Seat belt buckle latched, front passenger seat occupied.
OFF: Seat belt buckle not latched, front passenger seat not occupied.
Contrary to the DTC memory, actual values are updated continuously, even during diagnosis, so that, e.g. by moving components, or connections and wiring harnesses, intermittent failures may be indicated, recognized.
Additional Actual Values:
If so equipped, with Seat Occupied Recognition (SOR) with Automatic Child Seat Recognition (ACSR) the additional information is shown:
Function: F / SOR / ACSR
(SOR continues to be active regardless if MB Child seat "Babysafe" is not used or recognized).
Passenger seat: occupied / not occupied
Child seat: F /recognized / not used
Facing direction of child seat: F / forwards/ backwards
NOTE: The actual values: SOR/ACSR are updated approx. every 15 seconds.
