Refer to
HVAC Control
.
Circuit Description
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 high speed and series/parallel cooling fan relays.
Conditions for Setting the DTC
| • | The ignition is ON. |
| • | An improper voltage level has been detected on the Fan 2 control circuit. |
| • | The above conditions are present 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 the PCM or the fan relays. |
| 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 digital multimeter connected between the Fan 2 control circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the series/parallel fan relay and the high speed fan relay. A change in voltage will indicate the location of the malfunction. |
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, ignition 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 malfunctioning series/parallel or high speed cooling fan relay.
-
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 | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the voltage near the specified value? | B+ | |||
Does the current reading remain between the specified values? | 0.05-0.5 Amp (50-500 mA) | |||
Is voltage at the specified value? | 0 V | |||
5 | Locate and repair short to voltage in the fan 2 control circuit. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |
6 |
Is the fuse blown? | -- | ||
7 |
Is action complete? | -- | -- | |
8 |
Is voltage near the specified value? | B+ | ||
9 |
Was a problem found? | -- | ||
10 | Check for the following conditions:
Was a problem found? | -- | ||
11 |
Does the test light flash ON and OFF? | -- | Go to Diagnostic Aids | |
12 |
Was a problem found? | -- | ||
13 | Locate and repair open in the ignition feed circuit to the high speed cooling fan relay. Refer to Repair Procedures in Electrical Diagnosis. Is action complete? | -- | -- | |
14 | Replace the high speed cooling fan relay. Is action complete? | -- | -- | |
Replace the PCM. Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||
16 |
Does the scan tool indicate DTC P1652 failed this ignition? | -- | System OK |
