Page 1387 of 5267

P1281-ENGINE IS COLD TOO LONG
For a complete wiring diagramRefer to Section 8W.
When Monitored:
The ignition key on, engine running.
Set Condition:
The engine does not warm to 176 Deg. F while driving for 20 minutes after start.
Possible Causes
ENGINE COLD TOO LONG
ECT SENSOR OPERATION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.CHECK COOLING SYSTEM PERFORMANCE
NOTE: The best way to diagnose this DTC is to allow the vehicle to remain outside overnight in order to
have a completely cold soaked engine.
NOTE: Extremely cold outside ambient temperatures may cause this DTC to set.
Verify that the coolant level is not low and correct as necessary.
Start the engine.
With the scan tool, set the engine RPM to 1500 and allow the engine to warm up for 10-15 minutes.
With the scan tool, monitor the ENG COOLANT TMP DEG value during the warm up cycle. Make sure the transition
of temperature change is smooth.
Did the engine temperature reach a minimum of 80° C (176° F)?
Ye s>>
Go To 2
No>>
Refer to the Service Information for cooling system performance diagnosis. The most probable cause is
a Thermostat problem. Also, refer to any related TSBs.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ECT SENSOR OPERATION
WARNING: WARNING: MAKE SURE THE ENGINE COOLING SYSTEM IS COOL BEFORE REMOVING THE
PRESSURE CAP OR ANY HOSE. SEVERE PERSONAL INJURY MAY RESULT FROM ESCAPING HOT COOL-
ANT. THE COOLING SYSTEM IS PRESSURIZED WHEN HOT.
With the scan tool, read and record the ECT Sensor Temperature value.
Using the DRB Temperature Probe #CH7050, measure the engine coolant temperature.
NOTE: The t-stat housing area should be around 192-195 at start to open.
Is the ECT Sensor value with -15°C (5°F) of the temperature probe reading?
Ye s>>
Te s t C o m p l e t e .
No>>
Replace the ECT Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1389 of 5267

When Monitored:
With the ignition on and battery voltage above 10.4 volts.
Set Condition:
An open or shorted condition is detected in the Fuel Pump Relay Control circuit.
Possible Causes
FUEL PUMP RELAY OPERATION
FUEL PUMP RELAY
FUSED IGNITION SWITCH OUTPUT CIRCUIT
(K31) FUEL PUMP RELAY CONTROL CIRCUIT OPEN
(K31) FUEL PUMP RELAY CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.FUEL PUMP RELAY OPERATION
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool, actuate the Fuel Pump Relay.
Is the Fuel Pump Relay clicking?
Ye s>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.FUEL PUMP RELAY
Turn the ignition off.
Remove the Fuel Pump Relay.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the coil terminals of the Fuel Pump Relay.
Is the resistance between 50 and 90 ohms?
Ye s>>
Go To 3
No>>
Replace the Fuel Pump Relay.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
3.FUSED IGNITION SWITCH CIRCUIT OPEN
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch Output circuit in the Fuel Pump
Relay connector.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the Fused Ignition Switch Output circuit. Inspect the related fuse
and repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1390 of 5267

4.(K31) FUEL PUMP RELAY CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance of the (K31) Fuel Pump Relay Control circuit from the Fuel Pump Relay connector to the
PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (K31) Fuel Pump Relay Control circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.(K31) FUEL PUMP RELAY CONTROL CIRCUIT SHORT TO GROUND
Measure the resistance between ground and the (K31) Fuel Pump Relay Control circuit at the PDC.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K31) Fuel Pump Relay Control circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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4.THROTTLE BODY AND THROTTLE LINKAGE
Inspect the throttle body plate for carbon build up or other restrictions.
Inspect the throttle linkage for binding and smooth operation.
Ensure the throttle plate is resting on the stop at idle.
Remove IAC, inspect the pintle and its seating surface inside the throttlebody.
Were any problems found?
Ye s>>
Clean and/or replace the throttle body as needed.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.IAC DRIVER CIRCUITS OPEN
Turn the ignition off.
Disconnect IAC Motor harness connector.
Disconnect the PCM harness connectors.
Measure the resistance of each of the IAC Driver circuit from the IAC
Motor harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 6
No>>
Repair the open in the appropriate IAC Driver circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1397 of 5267
6.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit in the MAP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 7
7.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1399 of 5267

When Monitored:
With engine RPM +/- 64 of target idle and the throttle blade at closed throttle.
Set Condition:
Too small of a difference is seen between barometric pressure with ignition on (engine running) and manifold
vacuum for 8.80 seconds.
Possible Causes
GOOD TRIP EQUAL TO ZERO
MAP SENSOR VACUUM PORT
MAP SENSOR VOLTAGE BELOW 3.19 VOLTS
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
MAP SENSOR
(K1) MAP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(K1) MAP SENSOR SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
NOTE: If a MAP high or Low DTC set along with P1297, diagnose the High or Low DTC first before con-
tinuing.
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.MAP SENSOR VACUUM PORT
Turn the ignition off.
Remove the MAP Sensor.
Inspect the vacuum port, check for restrictions or any foreign materials.
Were any restriction found?
Ye s>>
Repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.MAP SENSOR VOLTAGE BELOW 3.19 VOLTS
Install the MAP Sensor.
Ignition on, engine not running.
With the scan tool, read the MAP Sensor voltage.
Is the voltage below 3.19 volts?
Ye s>>
Go To 4
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1402 of 5267
9.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit at the MAP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 10
10.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1405 of 5267

4.(K51) ASD RELAY CONTROL CIRCUIT OPEN
Disconnect the PCM harness connectors.
Measure the resistance of the (K51) ASD Relay Control circuit from the ASD Relay cavity in the PDC to the PCM
harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (K51) ASD Relay Control circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.(K51) ASD RELAY CONTROL CIRCUIT SHORT TO GROUND
Measure the resistance between ground and the (K51) ASD Relay Control circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K51) ASD Relay Control circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no more possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)