PINPOINT TEST G455141p1

PINPOINT TEST G455141p1 : FUEL FIRED HEATER CONTROL CIRCUIT

G455141t1 : CHECK THE FUEL FIRED HEATER CONTROL RELAY SUPPLY
1.

4. Fuel fired heater relay connector disconnected.
5. Key on, engine off.
6. Measure the voltage between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
relay power, pin 03

- Is the voltage between 9 volts and 15 volts?

-> YES
GO to Pinpoint Test G455141t2.

-> NO
NO supply to the fuel fired heater module relay. REPAIR the circuit as necessary.

G455141t2 : CHECK THE CONTROL LINE FOR SHORT CIRCUIT TO GROUND
1. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
relay signal, pin 01

- Is the resistance greater than 100 Kohms?

-> YES
GO to Pinpoint Test G455141t4.

-> NO
GO to Pinpoint Test 455141t3.

G455141t3 : CHECK WHETHER THE SHORT CIRCUIT TO GROUND IS IN THE FUEL FIRED HEATER MODULE RELAY HARNESS OR CONTROL MODULE
1. Key off.
2. ECM connector disconnected.
3. Key on, engine off.
4. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
relay signal, pin 01

- Is the resistance greater than 100 Kohms?

-> YES
SUSPECT: - ECM

-> NO
REPAIR the short circuit.

G455141t4 : CHECK THE CONTROL LINE FOR SHORT CIRCUIT TO POWER
1. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Positive post
relay signal, pin 01

- Is the resistance greater than 100 Kohms?

-> YES
GO to Pinpoint Test G455141t6.

-> NO
GO to Pinpoint Test G455141t5.

G455141t5 : CHECK WHETHER THE SHORT CIRCUIT TO POWER IS IN THE FUEL FIRED HEATER MODULE RELAY HARNESS OR CONTROL MODULE
1. Key off.
2. ECM connector disconnected.
3. Key on, engine off.
4. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Positive post
relay signal, pin 01

- Is the resistance greater than 100 Kohms?

-> YES
SUSPECT: - ECM

-> NO
REPAIR the short circuit.

G455141t6 : CHECK THE FUEL FIRED HEATER MODULE SIGNAL LINE FOR SHORT CIRCUIT TO GROUND
1. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
signal, pin 05

- Is the resistance greater than 100 Kohms?

-> YES
GO to Pinpoint Test G455141t8.

-> NO
GO to Pinpoint Test G455141t7.

G455141t7 : CHECK WHETHER THE SHORT CIRCUIT TO GROUND IS IN THE HARNESS OR THE FUEL FIRED HEATER ASSEMBLY
1. Key off.
2. Fuel fired heater assembly connector disconnected.
3. Key on, engine off.
4. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
signal, pin 05

- Is the resistance greater than 100 Kohms?

-> YES
INSTALL a new fuel fired heater assembly.

-> NO
REPAIR the short circuit.

G455141t8 : CHECK THE FUEL FIRED HEATER MODULE SIGNAL LINE FOR SHORT CIRCUIT TO POWER
1. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Negative post
signal, pin 05

- Is the resistance greater than 100 Kohms?

-> YES
GO to Pinpoint Test G455141t10.

-> NO
GO to Pinpoint Test G455141t9.

G455141t9 : CHECK WHETHER THE SHORT CIRCUIT TO POWER IS IN THE HARNESS OR THE FUEL FIRED HEATER ASSEMBLY
1. Key off.
2. Fuel fired heater assembly connector disconnected.
3. Key on, engine off.
4. Measure the resistance between:

Fuel fired heater relay Vehicle battery
connector, harness side
Fuel fired heater module Positive post
signal, pin 05

- Is the resistance greater than 100 Kohms?

-> YES
INSTALL a new fuel fired heater assembly.

-> NO
REPAIR the short circuit.

G455141t10 : CHECK THE FUEL FIRED HEATER SIGNAL LINE FOR OPEN CIRCUIT
1. Key off.
2. Fuel fired heater assembly connector disconnected.
3. Key on, engine off.
4. Measure the resistance between:

Fuel fired heater relay Fuel fired heater
connector, harness side connector, harness side
Fuel fired heater module Fuel fired heater module
signal, pin 05 signal, pin 05

- Is the resistance less than 10 Ohms?

-> YES
GO to Pinpoint Test G455141t11.

-> NO
REPAIR the open circuit.

G455141t11 : CHECK THE POWER TO THE FUEL FIRED HEATER MODULE
1. Measure the voltage between:

Fuel fired heater Vehicle battery
connector, harness side
Fuel fired heater module Negative post
power, pin 01

- Is the voltage between 9 volts and 15 volts?

-> YES
GO to Pinpoint Test G455141t12.

-> NO
NO supply to the fuel fired heater module circuit. REPAIR the circuit as necessary.

G455141t12 : CHECK THE IGNITION SUPPLY TO THE FUEL FIRED HEATER MODULE
1. Key on, engine off.
2. Measure the voltage between:

Fuel fired heater Vehicle battery
connector, harness side
Fuel fired heater module Negative post
ignition supply, pin 04

- Is the voltage between 9 volts and 15 volts?

-> YES
GO to Pinpoint Test G455141t13.

-> NO
NO ignition supply to the fuel fired heater module circuit. REPAIR the circuit as necessary.

G455141t13 : CHECK THE FUEL FIRED HEATER MODULE GROUND CIRCUIT
1. Measure the resistance between:

Fuel fired heater Vehicle battery
connector, harness side
Fuel fired heater module Negative post
ground, pin 02

- Is the resistance less than 10 Ohms?

-> YES
GO to Pinpoint Test G455141t14.

-> NO
REPAIR the open circuit.

G455141t14 : CHECK THE CONTROL LINE FOR CONTINUITY
1. ECM connector disconnected.
2. Measure the resistance between:

Fuel fired heater relay ECM connector,
connector, harness side harness side
Fuel fired heater module Fuel fired heater module
relay signal, pin 01 relay signal, pin 80

- 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. If no fault is found in the circuit, suspect the following component(s): - Fuel fired heater relay - Fuel fired heater assembly - ECM

-> NO
REPAIR the open circuit.