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	Cable colour	Component/Function	Input/Output	Test conditions	Across	Test reading	See
1	RD/WH	+30			1-B+	< 0.5 V
2	BK	Ground			2-B-	< 0.1 V
3	YE	MCC/ACC
4	VT	Fuel pump	Out		4-2	» 10 ohms
5		No connection
6	BN	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	Cable colour	Component/Function	Input/Output	Test conditions	Across	Test reading	See
1	VT	Water pump +	Out
2	BN	Water pump -	Out
3	BN	Combustion air fan -	Out
4	BK	Combustion air fan +	Out
5	WH	Glow plug +	Out		5-6	0.8-0.9 ohms
6	BN	Glow plug -	Out		5-6	0.8-0.9 ohms
7		No connection
8		No connection
9	RD	Engine coolant temperature sensor 2	In		9-10	As in diagram
10	RD	Engine coolant temperature sensor 2	In		9-10	As in diagram
11	BU	Engine coolant temperature sensor 1	In		11-12	As in diagram
12	BU	Engine coolant temperature sensor 1	In		11-12	As in diagram
13	BN	Flame temperature sensor	In		13-14	As in diagram
14	BU	Flame temperature sensor	In		13-14	As in diagram