AD83.70-S-6000C | Auxiliary heater (AHE) test of electrical system | 16.9.98 |
MODEL 638.0 /1 /2 as of 15.10.97 with CODE (H12) Hot water auxiliary heater
MODEL 638.0 /1 /2 with CODE (HZ5) Hot water auxiliary heater 10 kW with timer
Danger! | Risk of explosion from fuel vapors, risk of poisoning from combustion gases and risk of injury from burning during or after operation of the heater | Do not put stationary heater or engine with heater booster into operation in confined spaces or in the vicinity of tank installations. Allow heater to cool down after operation and wear protective gloves. | |
| Electrical wiring diagram | ||
| For model 638 with engines 111.948, 111.978, 601.978, 601.970 and model 638.244 with engine 104.900 only | ||
| Electrical wiring diagram | For models 638.094/194/294 only | |
| With a fault display, cables, fuses, connectors and connections must be checked for open-circuit, good contact and correct connection in accordance with the currently valid circuit diagram. | ||
Connection and use of the test equipment | |||
Auxiliary heater diagnosis, previous knowledge | |||
Auxiliary heater connector assignment | |||
Auxiliary heater diagnostic tools | |||
| If a water auxiliary heater with heater booster is fitted in the vehicle, code A87 is used in the documentation i.e. engine 611 with code H12. Otherwise code A34 is used. | ||
| Test steps 1-7, 15 and 16 can be carried out without disassembling heater unit. A34.1 is accessible without unscrewing heater unit. If the fault cannot be determined in the first step, it must be tested directly on the control unit. | ||
a | Battery voltage 11-14 V | ||
b | All connectors connected | ||
c | All fuses in order | ||
Test step | Test | ||
1 | Auxiliary heater operating unit, testing electrical system of auxiliary heater | Model 638 with engines 111.948, 111.978, 601.978, 601.970 and model 638.244 and engine 104.900 only | |
2 | Auxiliary heater operating unit, testing electrical system of auxiliary heater | Models 638.094/194/294 only | |
3 | Heater unit, testing electrical system of auxiliary heater | ||
4 | Operating unit switch-on signal, testing electrical system of auxiliary heater | ||
5 | Diagnostic cable, testing electrical system of auxiliary heater | ||
6 | Actuation of fan, testing electrical system of auxiliary heater | Model 638 with engines 111.948, 111.978, 601.978, 601.970 and model 638.244 and engine 104.900 only | |
7 | Actuation of fan, testing electrical system of auxiliary heater | Models 638.094/194/294 only | |
8 | Actuation of auxiliary pump, testing electrical system of auxiliary heater | ||
9 | Auxiliary heater relay, testing electrical system of auxiliary heater | Model 638 with engines 111.948, 111.978, 601.978, 601.970 and model 638.244 and engine 104.900 only | |
10 | Glow plug, testing electrical system of auxiliary heater | ||
11 | Fuel metering pump, testing electrical system of auxiliary heater | ||
12 | Overheat protector, testing electrical system of auxiliary heater | ||
13 | Coolant temperature switch, testing electrical system of auxiliary heater | ||
14 | Flame monitor, testing electrical system of auxiliary heater | ||
15 | Combustion air blower, testing electrical system of auxiliary heater | ||
16 | Radio module, testing electrical system AHE | Models 638.094/194/294 only | |
17 | Climate control pushbutton control unit switch-on signal, testing electrical system AHE | Models 638.094/194/294 only |
Referenced documents
- ad0000s1000az Connection and use of testing equipment
- ad8370s200001b Auxiliary heater (AHE) connector assignment
- ad8370s200002b Auxiliary heater (AHE) diagnosis tools
- ad8370s2000b Auxiliary heater (AHE) diagnosis previous knowledge
- ad8370s600001b Auxiliary heater (AHE) test of electrical system auxiliary heater operating unit
- ad8370s600001c Auxiliary heater (AHE) test of electrical system auxiliary heater operating unit
- ad8370s600002c Auxiliary heater (AHE) test of electrical system heater unit
- ad8370s600003c Auxiliary heater (AHE) test of electrical system switch-on signal from operating unit
- ad8370s600004c Auxiliary heater (AHE) test of electrical system diagnostic cable
- ad8370s600005b Auxiliary heater (AHE) test of electrical system fan actuation
- ad8370s600005c Auxiliary heater (AHE) test of electrical system fan actuation
- ad8370s600006b Auxiliary heater (AHE) test of electrical system auxiliary pump actuation
- ad8370s600007b Auxiliary heater (AHE) test of electrical system auxiliary heater relay
- ad8370s600009b Auxiliary heater (AHE) test of electrical system heating plug
- ad8370s600010c Auxiliary heater (AHE) test of electrical system fuel metering pump
- ad8370s600011b Auxiliary heater (AHE) test of electrical system overheating cutout
- ad8370s600012b Auxiliary heater (AHE) test of electrical system coolant temperature switch
- ad8370s600013b Auxiliary heater (AHE) test of electrical system flame monitor
- ad8370s600014b Auxiliary heater (AHE) test of electrical system combustion air blower
- ad8370s600073a ZHE test of electrical system two-way radio module
- ad8370s600074a ZHE test of electrical system air conditioning on signal from pushbutton control module
- as8370z000201a Risk of explosion caused by fuel vapors igniting, risk of poisoning caused by inhaling combustible gases and risk of injury caused by burns during and after operation of heater unit
- pe8370s2001c Wiring diagram of auxiliary heater (AHE)
- pe8370s2001d Wiring diagram of auxiliary heater (AHE)
- pe8370s2001e Wiring diagram of auxiliary heater (ACH)