P0683-GLOW PLUG MODULE SIGNAL CIRCUIT MALFUNCTION





For a complete wiring diagram Refer to Section 8W



Possible Causes
ENGINE CONTROL MODULE
GLOW PLUG MODULE
(D330)/(K202) GLOW PLUG MODULE SIGNAL/CONTROL CIRCUIT OPEN
(D330)/(K202) GLOW PLUG MODULE SIGNAL/CONTROL CIRCUIT SHORTED TO GROUND
(D330)/(K202) GLOW PLUG MODULE SIGNAL/CONTROL CIRCUIT SHORTED TO VOLTAGE
INTERMITTENT CONDITION




Diagnostic Test

1. CHECK FOR ACTIVE DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.


NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.


Turn the ignition on.
With the scan tool, erase ECM DTCs.
Perform several engine run cycles, turning the ignition off for at least 20 seconds between each engine run cycle.
Turn the ignition on and wait at least 90 seconds.
With the scan tool, read ECM DTCs.

Did this DTC set again?

Yes


No

2. (D330)/(K202) GLOW PLUG MODULE SIG/CONTROL CIRCUIT OPEN



Turn the ignition off.
Disconnect the Glow Plug Module harness connectors.
Disconnect the ECM harness connectors.
Measure the resistance of the (D330) Glow Plug Module Signal circuit between the Glow Plug Module harness and the ECM harness connector.
Measure the resistance of the (K202) Glow Plug Module Control circuit between the Glow Plug Module harness and the ECM harness connector.

Is the resistance below 10.0 ohms for both measurements?

Yes


No

3. (D330)/(K202) GLOW PLUG MODULE SIG/CONTROLCIRCUIT SHORTED TO GROUND



Measure the resistance between ground and the (D330) Glow Plug Module Signal circuit at the Glow Plug Module harness connector.
Measure the resistance between ground and the (K202) Glow Plug Module Control circuit at the Glow Plug Module harness connector.

Is the resistance above 1000 ohms for both measurements?

Yes


No

4. (D330)/(K202) GLOW PLUG MODULE SIG/CONTROL CIRCUIT SHORTED TO VOLTAGE



Remove the ASD Relay from the TIPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage of the (D330) Glow Plug Module Signal circuit at the Glow Plug Module harness connector.
Measure the voltage of the (K202) Glow Plug Module Control circuit at the Glow Plug Module harness connector.

Is the voltage below 1.0 volt for both measurements?

Yes


No

5. GLOW PLUG CONTROL MODULE

Turn the ignition off.
Remove the jumper wire and install the ASD Relay.
Replace the Glow Plug Module in accordance with the Service Information.
Reconnect all connectors.
Turn the ignition on.
With the scan tool, erase ECM DTCs.
Perform several engine run cycles, turning the ignition off for at least 20 seconds between each engine run cycle.
With the scan tool, read the ECM DTCs.

Did this DTC set again?

Yes


No