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Chrysler RG Voyager. Manual - part 414

Symptom:

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO
EARLY

When Monitored and Set Condition:

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO EARLY

When Monitored:

During after-run.

Set Condition:

The internal ECM timer determines that the ECM/PCM Relay has shut

off before the AFTER-RUN mode of operation.

POSSIBLE CAUSES

CHECK FOR OTHER DTCS

INTERMITTENT CONDITION

ECM/PCM RELAY

ECM/PCM RELAY CONTROL CIRCUIT OPEN INTERMITTENTLY

ENGINE CONTROL MODULE

TEST

ACTION

APPLICABILITY

Turn the ignition on.
With the DRB, check for additional DTCs.
Are other DTCs present?

All

Yes

→ Refer to the Symptom List and diagnose the other DTCs before

continuing.
Perform ROAD TEST VERIFICATION - VER-2.

→ Go To 2

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 DRB 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 DRB, erase ECM DTCs.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?

All

Yes

→ Go To 3

→ Go To 5

159

DRIVEABILITY - DIESEL

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Install a substitute relay in place of the ECM/PCM Relay.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Turn the ignition on.
With the DRBIII

t, erase ECM DTCs.

Did this DTC set again?

All

Yes

→ Go To 4

→ Replace the ECM/PCM Relay.

Perform ROAD TEST VERIFICATION - VER-2.

Turn the ignition off.
Remove the ECM/PCM Relay from the IPM.
Disconnect the ECM harness connectors.
Measure the resistance of the ECM/PCM Relay Control circuit while wiggling the
wiring harness and connectors between the ECM and the IPM.
Was the resistance above 10.0 ohms at any time while wiggling the wiring harness
and connectors?

All

Yes

→ Repair the ECM/PCM Relay Control circuit for an intermittent

open.
Perform ROAD TEST VERIFICATION - VER-2.

→ Replace and program the Engine Control Module in accordance

with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
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.

→ Test Complete.

160

DRIVEABILITY - DIESEL

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO EARLY —

Continued

Symptom:

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO
LATE

When Monitored and Set Condition:

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO LATE

When Monitored:

During after-run.

Set Condition:

The internal ECM timer determines that the ECM/PCM Relay remains on

too long when AFTER-RUN mode of operation.

POSSIBLE CAUSES

CHECK FOR OTHER DTCS

INTERMITTENT CONDITION

ECM/PCM RELAY

ECM/PCM RELAY CONTROL CIRCUIT SHORTED TO GROUND INTERMITTENTLY

ECM/PCM RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE

ENGINE CONTROL MODULE

TEST

ACTION

APPLICABILITY

Turn the ignition on.
With the DRB, check for additional DTCs.
Are other DTCs present?

All

Yes

→ Refer to the Symptom List and diagnose of the other DTCs before

continuing.
Perform ROAD TEST VERIFICATION - VER-2.

→ Go To 2

All

Yes

→ Go To 3

→ Go To 6

161

DRIVEABILITY - DIESEL

TEST

ACTION

APPLICABILITY

Turn the ignition off.
Install a substitute relay in place of the ECM/PCM Relay.
Turn the ignition on.
With the DRBIII

t, erase DTCs.

Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?

All

Yes

→ Go To 4

→ Replace the ECM/PCM Relay.

Perform ROAD TEST VERIFICATION - VER-2.

Turn the ignition off.
Remove the ECM/PCM Relay from the IPM.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the ECM/PCM Relay Control circuit
while wiggling the wiring harness and connectors.
Was the resistance below 1000 ohms at any time while wiggling the wiring harness
and connectors?

All

Yes

→ Repair the ECM/PCM Relay Control circuit for an intermittent

short to ground.
Perform ROAD TEST VERIFICATION - VER-2.

→ Go To 5

Turn the ignition off.
Remove the ECM/PCM Relay from the IPM.
Turn the ignition on.
Measure the voltage of the ECM/PCM Relay Output circuit.
Is the voltage below 0.5 volt?

All

Yes

→ Replace and program the Engine Control Module in accordance

with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.

→ Repair the ECM/PCM Relay Output circuit for a short to voltage.

Perform ROAD TEST VERIFICATION - VER-2.

162

DRIVEABILITY - DIESEL

P0685-ECM/PCM RELAY CONTROL CIRCUIT SHUTS OFF TOO LATE —

Continued

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