Actron 9640 User Manual

The KOER Glow Plug is an on-demand test which activates the glow plug relay 

and detects any difference in the amount of current between both banks of glow 

plugs. DTCs returned from the test indicate which bank has failed glow plugs 

or failed wiring.

✓

Battery Voltage must be between 11.8 and 14.0 volts for the Glow Plug

Test. To maintain battery voltage, increase engine RPM. If required,

Select KOER Glow Plug from the 

Quick Tests screen. Perform the 

following:

1) Set Parking Brake.
2) Transmission In Park Or Neutral.
3) Turn A/C Off.
4) Start Engine — Let Idle Until Hot.
5) Turn Ign Key Off.
6) Wait 10 Seconds. Start Engine — Let Idle. 

When the vehicle has finished the test, 

the DTCs found display on the screen. 

If no codes are read, the System Pass 

screen is displayed.

Use 

UP/DOWN arrow keys to view 

Codes. 

Press the 

FUNC key to return to the Ford Function List or BACK to return to 

the Quick Tests screen.

The KOER Cyl. Cont. is an on-demand test performed with the engine running, 

the A/C OFF and engine oil temperature above 76.6C (170°F). This test 

determines that all cylinders are contributing equally to engine performance.

The PCM first tests the cylinders in numeric order (1 – 8) for a bad/weak 

cylinder. If all cylinders check good, a 4 cylinder test is then executed (if a weak 

cylinder is detected in the 8 cylinder test, the four cylinder test will not be 

started).

Quick Tests    

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` KOER Glow Plug   ] 

KOER Cyl. Cont.
KOER Switch     ~

DTCs Found: 2
Use [ To View DTCs
Write Down Codes
For Reference.    ~