AD83.70-W-6000-29C | AHE test of electrical system temperature sensor open circuit |
| Scope of test | Measuring instrument/ Test connection | Operation/Requirement | Specified value | Possible cause/Remedy | ||
1.0 | Water temperature sensor –//– Cable harness |
14/8 | G |
14/ 10 | Ignition: OFF Heater unit: OFF Open flap on air recirculation box. Disconnect 14-pin plug connection on vehicle blower. | 700–1300 Ω (at coolant temperature approx. 20 °C) | Value in order: 1.2 Value > 30 kΩ: 1.1 |
1.1 | Water temperature sensor –//– Internal resistance |
12/8 |
| Heater unit 12/ 10 | 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 12-pin plug connection on heater unit | 700–1300 Ω (at coolant temperature approx. 20 °C) | Value in order: Cable / plug connection from air recirculation box to heater unit (open-circuit). Value > 30 kΩ: Replace water temperature sensor on trial. Collect draining coolant. |
1.2 | Water temperature sensor –//– Cable harness and control unit |
A5 | Z13 |
A8 | Ignition: OFF Heater unit: OFF Re-connect 14-pin plug connection G on vehicle blower. Disconnect 13-pin plug A on control unit. | 700–1300 Ω (at coolant temperature approx. 20 °C) | Value in order: Replace control unit (Z13) on trial. Value > 30 kΩ: Cable to air recirculation box (open-circuit). Plug connection behind radio console or FF8 under electrical compartment (open-circuit). If no open-circuit can be detected but fault code re-appears, check cable to control unit (cable-short or short-circuit to positive cable or loose contact). |