Trouble code P1652 means: Cooling Fan 2 Relay Control Circuit
Malfunction
I would start by checking power supply to
the cooling fans,making sure the coolant system is full,& using a
scn tool to verify the proper operation of the cooling fan system.Here
is some info to help you.
The Powertrain Control Module (PCM)
controls the operation of the cooling fans. This is accomplished by
providing a ground path for the cooling fan relay coils within the PCM.
The relay contacts will close and complete the circuit between the
fusible link at the battery junction block and the fan motors. Whenever
there is a fan ON request both fans will be running.
Power for the
fan motors is supplied through a fusible link at the battery junction
block. Battery positive voltage is applied to the cooling fan relay
contacts and coils. The cooling fan relays are energized when current
flows through the relay coils to ground at the PCM. The cooling fan
relay #1 control circuit is used for low speed cooling fan operation.
The cooling fan relay #1 control circuit and the cooling fan relay #2
and #3 control circuit are both grounded for high speed fan operation.
The cooling fan relay control circuits are monitored by the PCM. Before
using the Electric Cooling Fans diagnostic tables be sure to perform the
Powertrain On-Board Diagnostic System Check. If diagnostic trouble
codes P1651 or P1652 are present, use the appropriate DTC diagnostic
tables prior to performing Electric Cooling Fans diagnostics.
Important:
When certain Diagnostic Trouble Codes (DTCs) are present, the
PCM may command the cooling fans to run all the time. It is important to
perform the Powertrain On-Board Diagnostic System check prior to
diagnosing the engine cooling fans.The PCM will complete the
ground path for cooling fan relay #1 under any of the following
conditions:
- When engine coolant temperature exceeds 105°C
(221°F)
- When A/C is requested and
ambient temperature is greater than 10°C (50°F)
- When
A/C refrigerant pressure is greater than 190 psi (2 volts)
For
high speed cooling fans operation, the PCM will delay control of the
cooling fan #2 and #3 relays for 6 seconds. The 6 second delay ensures
that the cooling fan electrical load will not exceed the capacity of the
system. The PCM will complete the ground paths for cooling fan relays
#1, #2, and #3 under any of the following conditions:
- When
engine coolant temperature exceeds 113°C (235°F)
- When
A/C refrigerant pressure is greater than 275 psi (2.9 volts)
If
a problem that involves the low speed cooling fan relay control circuit
(cooling fan relay #1 control) exists, DTC P1651 should set. If the
problem affects the high speed cooling fan relay control circuit
(cooling fan relay #2 and #3 control), DTC P1652 should set. A problem
with the ECT sensor should set DTC P0117, P0118, P1114, or P1115. Any of
these DTCs will affect cooling fan operation and should be diagnosed
before using the Electric Cooling Fan Diagnosis table. The Electric
Cooling Fan Diagnosis table should be used to diagnose the PCM
controlled cooling fans only if no DTC is set.
Hope this help to solve your poblem (remember rated and comment this help).
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