DTC P1652 Cooling Fan Relay 2 Control Circuit. Pontiac Grand Prix 1997

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 1997 🢒 Grand Prix 🢒 Engine 🢒 Engine Controls - 3.1L 🢒 DTC P1652 Cooling Fan Relay 2 Control Circuit

Refer to

Coolant Fans

Engine Controls Components
Information Sensors
A/C Compressor Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
.

Output Driver Modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and Transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. Unlike the Quad Driver Modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. DTC P1652 set indicates an improper voltage level has been detected on ODM B output 2, which controls the cool relay and cool fan 2 relays.

Conditions for Setting the DTC

•	Ignition is ON.

•	An improper voltage level has been detected on ODM B output 2 (cool relay and cool fan 2 relays).

•	Above conditions for at least 30 seconds.

Action Taken When the DTC Sets

•	The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.

•	The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

•	The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.

•	The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared by using the scan tool.

Diagnostic Aids

Check for the following conditions:

•	Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

•

Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a DMM connected to the cool relay and cool fan 2 relays driver circuit at the PCM harness connector while moving connectors and wiring harnesses related to the cool relay and cool fan 2 relays. A change in voltage will indicate the location of the fault.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

Normally, battery feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.

Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.

Checks for a short to B+ on the cooling fan relay #2 and #3 control circuit.

This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

Step

Action

Value(s)

Yes

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

Turn off the ignition switch.
Disconnect the PCM.
Turn on the ignition switch.
Using a J 39200 Digital Multimeter, measure voltage between the cool relay and cool fan 2 relays control circuit at the PCM harness connector and ground.

Is the voltage near the specified value?

B+

Go to Step 3

Go to Step 6

Disconnect the right engine cooling fan.
Connect the digital multimeter to measure current between the cool relay and cool fan 2 relays control circuit at the PCM harness connector and ground.
Monitor the current reading on the digital multimeter for at least 2 minutes.

Does the current reading remain between the specified values?

0.1 to 0.5 Amps

(100 to 500 mA)

Go to Step 11

Go to Step 4

Disconnect engine cool relay and cool fan 2 relays (leave the PCM disconnected).
Reconnect the right engine cooling fan.
Using the digital multimeter, measure voltage between the the cool relay and cool fan 2 relays control circuit and ground.

Is voltage at the specified value?

0 V

Go to Step 14

Go to Step 5

Locate and repair short to voltage in the cool relay and cool fan 2 relays control circuit. Refer to Repair Procedures in Electrical Diagnosis.

Is action complete?

Go to Step 18

Turn off the ignition switch.
Check the COOL FAN 2 fuse.

Is the fuse open?

Go to Step 7

Go to Step 8

Locate and repair short to ground in the battery feed circuit for the cool relay and cool fan 2 relays. Refer to Fuse Block Details in Electrical Diagnosis.
Replace the fuse.

Is action complete?

Go to Step 18

Disconnect the COOL Relay.
Turn on the ignition switch.
Measure voltage between the battery feed circuit at cool relay and ground.

Is voltage near the specified value?

B+

Go to Step 9

Go to Step 13

Check the cool relay and cool fan 2 relay control circuit for an open or a short to ground.
If a problem is found, repair the control circuit. Refer to Repair Procedures in Electrical Diagnosis.

Was a problem found?

Go to Step 18

Go to Step 10

Check for the following conditions:

•	The cool relay and cool fan 2 relay control circuit for poor connections at the cooling fan relays.

•	The battery feed circuit for poor connections at the cooling fan relays.

•	The cool relay and cool fan 2 relay control circuit for a poor connection at the PCM.

Was a problem found?

Go to Step 18

Refer to Diagnostic Aids

Turn off the ignition switch.
Reconnect the right cooling fan.
Reconnect the PCM.
Disconnect cool relay.
Turn on the ignition switch.
Connect a J 35616-200 Unpowered Test Light between the cool relay and cool fan 2 relay control and B+.
Using the scan tool outputs test function, cycle high speed fans on and off .

After 10 seconds does the test light flash on and off ?

Refer to Diagnostic Aids

Go to Step 12

Check the cool relay and cool fan 2 relay control circuit for a poor connection at the PCM.
If a problem is found, replace faulty terminal. Refer to Repair Procedures in Electrical Diagnosis.

Was a problem found?

Go to Step 18

Go to Step 15

Locate and repair open in battery feed circuit to the cooling fan relay(s) coil. Refer to Repair Procedures in Electrical Diagnosis.

Is action complete?

Go to Step 18

Reconnect cool fan 2 relay.
Install the DMM to measure current between cool relay and cool fan 2 relay control circuit and ground.
Monitor the current reading on the digital multimeter for at least 2 minutes.

Does the current reading remain below the specified value?

0.25 Amp

(250 mA)

Go to Step 16

Go to Step 17

Replace the PCM.

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is action complete?

Go to Step 18

Replace cool relay.

Is action complete?

Go to Step 18

Replace cool fan 2 relay.

Is action complete?

Go to Step 18

Turn off the ignition switch.
Reconnect any relay, cooling fan, and PCM connectors that were disconnected in the previous step.
Turn on the ignition switch.
Review and record scan tool Fail Records data.
Clear DTCs.
Operate the vehicle within Fail Records conditions as noted.
Using a scan tool, monitor Specific DTC info for DTC P1652 until the DTC P1652 test runs

Does the scan tool indicate DTC P1652 failed this ignition?

Go to Step 2

System OK

Coolant Fans

Circuit Description

Conditions for Setting the DTC

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

Test Description