Symptom:
P1690-FAN CONTROL SHORT CIRCUIT
When Monitored and Set Condition:
P1690-FAN CONTROL SHORT CIRCUIT
When Monitored:
With the ignition on and the ECM attempting to enable the radiator
fan relay.
Set Condition:
The ECM detects excessive current draw on the radiator fan relay control
circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
SUBSTITUTE RADIATOR FAN RELAY
RADIATOR FAN RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST
ACTION
APPLICABILITY
1
Turn the ignition on.
With the DRB, actuate the Radiator Fan Relay.
Does the Radiator Fan cycle on and off?
All
Yes
→
Go To
2
No
→
Go To
3
2
WARNING: KEEP CLEAR OF THE ENGINE’S MOVING PARTS.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?
All
Yes
→
Repair as necessary
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Test Complete.
156
DRIVEABILITY - DIESEL