AD83.70-W-6000-36C | AHE test of electrical system flame monitor short to ground |
| Scope of test | Measuring instrument/ Test connection | Operation/Requirement | Specified value | Possible cause/Remedy | ||
1.0 | Flame sensor Cables, internal resistance |
14/8 | G |
14/9 | Ignition: OFF Heater unit: OFF Open flap on air recirculation box. Disconnect 14-pin plug connection on vehicle blower. | 700–1300 Ω (at approx. | Value in order: 1.2 Value < 50 Ω: 1.1 |
1.1 | Flame sensor Internal resistance |
12/7 | Heater unit |
12/9 | Ignition: OFF Heater unit: OFF Allow engine and heater unit to cool down if necessary. Remove cover in front right wheel housing and remove heater unit. Disconnect plug connection on heater unit. | 700–1300 Ω (at approx. | Value in order: Cable / plug connection from air recirculation box to heater unit (short-circuit to ground). Value < 50 Ω: Replace flame sensor on trial. |
1.2 | Flame sensor Cable harness, control unit |
A5 | Z13 |
A4 | Ignition: OFF Heater unit: OFF Re-connect plug connection G on vehicle blower. Disconnect 13-pin plug A on control unit. | 700–1300 Ω (at approx. | Value in order: Check whether sporadic short-circuit to ground is possible (chafed cable on plug connection etc.). If no fault visible Replace control unit (Z13) on trial. Value < 5 Ω: Cable to control unit (short-circuit to ground). Plug connection behind radio console or under electrical compartment (short-circuit to ground). |