PINPOINT TEST G528708p1 : CHECK THE EGR STEPPER SUPPLY AND CONTROL CIRCUITS

Pinpoint Tests

CAUTION: When probing connectors to take measurements in the course of the pinpoint tests, use the adaptor kit, part number 3548-1358-00.

NOTE:
- When performing electrical voltage or resistance tests, always use a digital multimeter (DMM) accurate to 3 decimal places, and with an up-to-date calibration certificate. When testing resistance, always take the resistance of the DMM leads into account.
- Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

PINPOINT TEST G528708p1 : CHECK THE EGR STEPPER SUPPLY AND CONTROL CIRCUITS

G528708t1 : CHECK THE EGR STEPPER SUPPLY VOLTAGE CIRCUITS
1. Key off.
2. Disconnect the EGR stepper electrical connector, PI15.
3. Key on, ignition off. Make sure the EMS relay is energized.
4. Measure the voltage between:

EGR stepper connector, PI15 Battery
Pin 02 Negative terminal
Pin 05

- Is the voltage less than 10 volts?

-> YES
REPAIR the relevant EGR stepper supply voltage circuit. This circuit includes the front power distribution box (fuse 14) and the EMS control relay. CLEAR the DTCs and test the system for normal operation.

-> NO
GO to Pinpoint Test G528708t2.

G528708t2 : CHECK THE EGR STEPPER CONTROL CIRCUITS FOR SHORT CIRCUIT TO GROUND
1. Key off.
2. Measure the resistance between:

EGR stepper connector, PI15 Battery
Pin 04 Negative terminal
Pin 01
Pin 06
Pin 03

- Is the resistance less than 10,000 ohms?

-> YES
REPAIR the short circuit. CLEAR the DTCs and test the system for normal operation.

-> NO
GO to Pinpoint Test G528708t3.

G528708t3 : CHECK THE EGR STEPPER CONTROL CIRCUITS FOR SHORT CIRCUIT TO POWER
1. Measure the resistance between:

EGR stepper connector, PI15 Battery
Pin 04 Positive terminal
Pin 01
Pin 06
Pin 03

- Is the resistance less than 10,000 ohms?

-> YES
REPAIR the short circuit. CLEAR the DTCs and test the system for normal operation.

-> NO
GO to Pinpoint Test G528708t4.

G528708t4 : CHECK THE EGR STEPPER CONTROL CIRCUITS FOR HIGH RESISTANCE
1. Key off.
2. Disconnect the ECM electrical connector, EC300.
3. Measure the resistance between:

EGR stepper connector, PI15 ECM connector, EC300
Pin 04 Pin 53
Pin 01 Pin 52
Pin 06 Pin 51
Pin 03 Pin 50

- Is the resistance greater than 5 ohms?

-> YES
REPAIR the high resistance circuit. CLEAR the DTC and test the system for normal operation.

-> NO
INSTALL a new EGR valve. CLEAR the DTC and test the system for normal operation. Refer to the warranty policy and procedures manual if an ECM is suspect.