Pinpoint Test S : Insufficient Heat In Auto Start-Stop Mode Only

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

S1 CHECK THE CABIN HEATER COOLANT PUMP

NOTE: The engine must be auto-stopped to request the cabin heater coolant pump on. Refer to the Owner's Literature, Unique Driving Characteristics for full auto start-stop enabling/disabling information.
- Start the vehicle and allow engine to reach normal operating temperatures.
- Using the HVAC controls, select panel mode, set temperature to full hot and set blower speed to low.
- Drive the vehicle above 4 km/h (3 mph).
- Stop the vehicle on a level surface.
- Make sure the steering wheel is set to the straight ahead position.
- Keep the transmission selector lever in position D, brake pedal pressed and doors closed.
- Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
- Monitor the PCM coolant pump status (COOLPMP_A_STAT) PID for at least 1 minute.
Does the cabin heater coolant pump turn on?

Yes GO to S6

No GO to S2

S2 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TO VOLTAGE

Disconnect BJB Fuse 36 (10A).

Disconnect PCM .

Disconnect Cabin heater coolant pump .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY	Ground
	Courtesy of FORD MOTOR COMPANY	Ground

Is there any voltage present?

Yes	REPAIR the circuit.

GO to S3

S3 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY	Ground
	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes

GO to S4

No	REPAIR the circuit.

S4 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY	Ground

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY	BJB fuse 36 (10A) cavity, component side

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY

Are the resistances less than 3 ohms?

Yes

GO to S5

No	REPAIR the circuit.

S5 CHECK THE CABIN HEATER COOLANT PUMP CIRCUITS FOR A SHORT TOGETHER

Measure:

Positive Lead	Measurement / Action	Negative Lead
	Courtesy of FORD MOTOR COMPANY
	Courtesy of FORD MOTOR COMPANY
	Courtesy of FORD MOTOR COMPANY

Are the resistances greater than 10, 000 ohms?

Yes

GO to S6

No	REPAIR the circuit.

S6 CHECK THE ENGINE COOLANT LEVEL

NOTE: Allow the engine to cool before checking the engine coolant level.
- Visually inspect the engine coolant level at the degas bottle.
Is the engine coolant level within specifications?

Yes GO to S7

No REFER to the ENGINE COOLING - 3.5L ECOBOOST (272KW/370PS) .

S7 CLEAR ALL PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES

Connect all disconnected connectors. Make sure they seat and latch correctly.

Ignition ON.

Using a diagnostic scan tool, CLEAR all PCM Diagnostic Trouble Codes (DTCs).

NOTE: The engine must be auto-stopped to request the cabin heater coolant pump on. Refer to the Owner's Literature for full Auto Start-Stop enabling/disabling.

Start the vehicle and allow engine to reach normal operating temperatures.

Using the HVAC controls, select panel mode, set temperature to full hot and set blower speed to low.

Drive the vehicle above 4 km/h (3 mph).

Stop the vehicle on a level surface.

Make sure the steering wheel is set to the straight ahead position.

Keep the transmission selector lever in position D, brake pedal pressed and doors closed.

Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).

Monitor the PCM coolant pump status (COOLPMP_A_STAT) PID for at least 1 minute.

Does the cabin coolant pump turn on?

Yes

If the cabin coolant pump runs for 10 seconds on and 10 seconds off, PURGE the air from the coolant system.If the cabin coolant pump runs normally, the system is operating correctly at this time. The concern may have been caused by pump connections. ADDRESS the root cause of any connector or pin issues.

No	INSTALL a new cabin heater coolant pump. REFER to the appropriate GENERAL PROCEDURES . TEST the system for normal operation. If the concern is still present, GO to S8

S8 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all PCM connectors.

Repair:
- corrosion (replace connector or terminals - clean module pins)
- damaged or bent pins - replace terminals/pins
- pushed-out pins - replace pins as necessary

Reconnect all PCM connectors. Make sure they seat and latch correctly.

Operate the system and verify the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM GUIDED ROUTINE TESTING -- NAVIGATOR .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.