Test readings, control module connections

Test readings, control module connections

Extent

The following pages contain values and instructions for obtaining readings of signals and levels on the heater.

Remember

•	Note the test conditions and use your common sense when judging the test results.

•	Unless otherwise stated, the test readings presented are with the ignition switch in the ON position.

•	First check that the control module is supplied with current and grounded.

•	Then check all sensor inputs and signals from other systems.

•	Finally, check the control module outputs. Remember that the test readings do not indicate whether or not the actuator is in working order.

•	If any reading is not OK, consult the wiring diagram to trace the leads, connectors or components which ought to be checked more thoroughly.

•	The test readings given apply to a correctly calibrated Fluke 88/97.

•	The readings %(+) and ms(+) indicate the pulse ratio and pulse duration. A test instrument capable of measuring both pulse ratio and pulse duration must be used. The + sign denotes a positive trigger pulse (TRIG+).

Connector B1

> = greater than; < = less than; » = approximately equal to; ∼= alternating current

Pins with no additional comments have no pin connection. (LP = LOGIC PROBE; P = select pulse; p = perceptible pulses)

Pin	Component/Function	Input/Output	Test conditions	Across	Test reading	See
1	+30			1-B+	< 0.5 V
2	Ground			2-B-	< 0.1 V
3	MCC/ACC
4	Fuel pump	Output		4-2	» 10 Ohm
5	No connection
6	Main relay, heater
7	No connection
8	No connection

Connector B2

> = greater than; < = less than; » = approximately equal to; ∼= alternating current

Pins with no additional comments have no pin connection. (LP = LOGIC PROBE; P = select pulse; p = perceptible pulses)

Pin	Component/Function	Input/Output	Test conditions	Across	Test reading	See
1	Water pump +	Output
2	Water pump -	Output
3	Combustion air fan -	Output
4	Combustion air fan +	Output
5	Glow plug +	Output		5-6	0,8 - 0,9 Ohm
6	Glow plug -	Output		5-6	0,8 - 0,9 Ohm
7	No connection
8	No connection
9	Engine coolant temperature sensor 2	Input		9-10	As in diagram
10	Engine coolant temperature sensor 2	Input		9-10	As in diagram
11	Engine coolant temperature sensor 1	Input		11-12	As in diagram
12	Engine coolant temperature sensor 1	Input		11-12	As in diagram
13	Flame temperature sensor	Input		13-14	As in diagram
14	Flame temperature sensor	Input		13-14	As in diagram