Jaguar XJ (X350). Manual — part 766

PINPOINT TEST G552799p1 : GLOW
PLUG CONTROL MODULE (GPCM)
CONTROL CIRCUIT

G552799t1 : CHECK THE GPCM CONTROL CIRCUIT FOR SHORT CIRCUIT TO
GROUND

1.

Circuit

Pin

Ground

01

Control from ECM

02

Power supply from FPDB 03

Logic monitor

05

2.

Circuit

Pin

Glow plug control module signal G3

Logic monitor

E3

3. Key off. 4. Disconnect the GPCM electrical connector, EC69. 5. Measure the resistance between:

E69, harness side

Battery

Pin 02

Negative terminal

Is the resistance greater than 10 Kohms?

-> Yes

GO to Pinpoint Test G552799t3.

-> No

GO to Pinpoint Test G552799t2.

G552799t2 : CHECK WHETHER THE SHORT CIRCUIT IS IN THE HARNESS OR
THE MODULE

1. Disconnect the ECM connector, C100. 2. Measure the resistance between:

EC69, harness side

Battery

Pin 02

Negative terminal

Is the resistance greater than 10 Kohms?

-> Yes

An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other

physical damage to the harness.

-> No

REPAIR the short circuit. For additional information, refer to the wiring diagrams. Clear the DTC, test

the system for normal operation.

G552799t3 : CHECK THE GPCM CONTROL CIRCUIT FOR SHORT CIRCUIT TO
POWER

1. Key off. 2. Measure the resistance between:

EC69, harness side

Battery

www.

Pin 02

Positive terminal

Is the resistance greater than 10 Kohms?

-> Yes

GO to Pinpoint Test G552799t5.

-> No

GO to Pinpoint Test G552799t4.

G552799t4 : CHECK WHETHER THE SHORT CIRCUIT IS IN THE HARNESS OR
THE module

1. Disconnect the ECM connector, C100. 2. Measure the resistance between:

EC69, harness side

Battery

Pin 02

Positive terminal

Is the resistance greater than 10 Kohms?

-> Yes

An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other

physical damage to the harness.

-> No

REPAIR the short circuit. For additional information, refer to the wiring diagrams. Clear the DTC, test

the system for normal operation.

G552799t5 : CHECK THE GPCM CONTROL CIRCUIT FOR HIGH RESISTANCE

1. Disconnect the ECM connector, C100. 2. Measure the resistance between:

EC69, harness side C100, harness side

Pin 02

Pin G3

Is the resistance less than 10 ohms?

-> Yes

An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other

physical damage to the harness. Refer to the warranty policy and procedures manual if a module is

suspect.

-> No

REPAIR the high resistance circuit. This circuit includes connector, PI41. For additional information,

refer to the wiring diagrams. Clear the DTC, test the system for normal operation.

PINPOINT TEST G552799p2 : GLOW
PLUG CONTROL MODULE (GPCM)
OUTPUT

G552799t6 : CHECK THE PERMANENT POWER SUPPLY TO THE GPCM

1.

Circuit

Pin

Ground

01

Control from ECM

02

Power supply from FPDB 03

Logic monitor

05

2.

www.