Jeep XJ. Manual - part 621
Symptom:
P1635-GLOW RELAY 1 CONTROLLER OPEN CIRCUIT
When Monitored and Set Condition:
P1635-GLOW RELAY 1 CONTROLLER OPEN CIRCUIT
When Monitored:
With the ignition on.
Set Condition:
The ECM detects an open or a short to ground on the glow plug relay 1
control circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
ASD/DIESEL POWER RELAY OUTPUT CIRCUIT OPEN
SUBSTITUTE GLOW PLUG RELAY
GLOW PLUG RELAY CONTROL CIRCUIT SHORTED TO GROUND
GLOW PLUG RELAY CONTROL CIRCUIT OPEN
ENGINE CONTROL MODULE
TEST
ACTION
APPLICABILITY
1
Turn the ignition on.
With the DRB, actuate the Glow Plug Relay.
Is the Glow Plug Relay clicking?
All
Yes
→
No
→
NOTE: Stop the Glow Plug Relay actuation by the DRB.
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.
136
DRIVEABILITY - DIESEL