Refer to
AIR ,Gen Control Volts Lamp, Low Oil
.
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 transmission 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 P1642 set indicates an improper voltage level has been detected on ODM A output 2, which controls the Secondary Air Injection relay.
Conditions for Setting the DTC
| • | Ignition is ON. |
| • | An improper voltage level has been detected on ODM A Output 2 (the Secondary Air Injection Relay Driver circuit). |
| • | Above condition for at least 30 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the MIL during the second key cycle in which the DTC sets. |
| • | The PCM will store conditions whcih were present when the DTC set as Freeze Frame and Fail Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present. |
| • | A history DTC P1642 will clear after 40 consecutive warm-up cycles have occurred without a fault. |
| • | DTC P1642 can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Check the following conditions:
| • | Poor connection at PCM. Inspect harness connectors for bascked out terminals, improper mating, broken locks, improperly formed or damaged terminal, and poor terminal to wire connection. |
| • | Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, perform the following check: |
| - | Disconnect the PCM, turn the ignition ON. |
| - | Connect a DVM to the Secondary Air Injection Relay driver circuit at the PCM harness connector. |
| - | Observe the DVM while moving the connectors and wiring. |
A change in voltage will indicate the location of the fault.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain OBD System Check | |||||
2 | Is DTC P0102, P0135, P0141, P1406, P1442 and/or P1655 also set? | -- | ||||||
3 |
Was a problem found? | -- | Refer to Diagnostic Aids | |||||
4 |
Is the testlight ON? | -- | ||||||
5 |
Was a problem found? | -- | ||||||
6 |
Is the testlight ON? | -- | ||||||
7 |
Is the testlight ON? | -- | ||||||
8 | Locate and repair open in the igntion feed terminal to the Secondary Air Injection system relay (refer to Repair Procedures in Electrical Diagnosis, Section 8A-5).Is action complete? | -- | -- | |||||
9 | Locate and repair short to ground in the Secondary Air Injection driver circuit (refer to Repair Procedures in Electrical Diagnosis, Section 8A-5). Is action complete? | -- | -- | |||||
10 |
Does the DVM display a voltage above specified value | 0V | ||||||
11 | Locate and repair short to voltage or short to the 5 volt reference circuit (refer to Repair Procedures in Electrical Diagnosis, Section 8A-5). Is action complete? | -- | -- | |||||
12 |
Was a problem found? | -- | ||||||
13 |
Was a problem found? | -- | ||||||
14 |
Was a problem found? | -- | ||||||
15 | Replace the Secondary Air Injection system relay. Is action complete? | -- | -- | |||||
Replace the PCM.Important: replacement PCM must be programmed. Refer to ON-Vehicle Service in Powertran Control Moduel and Sensore for procedures. Is action complete? | -- | -- | ||||||
17 |
Does scan tool indicate DTC P1642 failed this ign? | -- | System OK |
