| Test | TECH 1 | Notes | Nominal Values | Possible |
|---|---|---|---|---|
| Step | Display | Trouble | ||
| No. | Codes | |||
| 03 | EXHAUST CODING | Ignition ON | ||
| Engine at idle speed | ||||
| With closed loop systems: | ||||
| C 20 XE | US 5 V | - | ||
| With open loop systems: | ||||
| 20 XE, 20 XEJ | ECE 0 V |
Before trouble-shooting, it should be established whether the exhaust coding is correct for the relevant engine.
- see section 5.2.3 -
Trouble-shooting: Nominal Value: Cause of Fault:
(If nominal value is not attained)
· Remove control unit plug Ter. 20 unoccupied · Incorrect wiring harness installed
cable cover
· Control unit defective
· Measure voltage
at Ter. 20 against
ground Ter. 14 using
multimeter
Ignition ON 4.6 to 5.0 V
Note: To remove the control unit plug cable cover, 3 bolts should be loosened and the cover pulled off upwards.
When doing this, do not disconnect control unit from the wiring harness if possible, as this may clear stored trouble codes.