Circuit Description
The EGR flow is controlled by the vacuum actuated EGR valve. The EGR pulse width modulated solenoid meters the vacuum level at the EGR valve actuator as commanded by the PCM. When the PCM is commanding the EGR solenoid ON, the voltage potential of the circuit will be low (near 0 volts). When the PCM is commanding the EGR solenoid OFF, the voltage potential of the circuit will be high (near battery volts). The primary function of the PCM in this circuit is to supply the ground for the EGR solenoid. This is a type B code.
Conditions for Setting the DTC
| • | PCM requested EGR solenoid ON. |
| • | Voltage on EGR solenoid control circuit high (near battery volts). |
| • | 2 consecutive faults detected. |
| • | Conditions met for 2 seconds. |
or
| • | PCM requested EGR solenoid OFF. |
| • | Voltage on EGR solenoid control circuit low (near 0 volts). |
| • | 2 consecutive faults detected. |
| • | Conditions met for 2 seconds. |
Action Taken When the DTC Sets
No EGR. Possible black smoke on acceleration.
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL off after three consecutive trips without a fault condition. |
| • | A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle. |
| • | Use of a Scan Tool |
Diagnostic Aids
The scan tool has a 5 second ON time abort. The EGR solenoid can be commanded ON for as many times as needed, in 5 second intervals. Its possible other EGR DTCs may set along with DTC P1655. This diagnostic can be checked at key up. A quick operational check can be made by commanding the EGR solenoid ON and OFF with the scan tool while monitoring Actual EGR. Actual EGR will display Baro (approximately) when EGR solenoid is OFF. Full EGR will be achieved when EGR solenoid is commanded ON with the scan tool.
Test Description
Number(s) below refer to the Step number(s) on the Diagnostic Table.
-
Be sure that both the ON and OFF states are commanded. Repeat the commands as many times as necessary. This Step will determine if this DTC is a current or intermittent.
-
This check can detect a partially shorted coil which would cause excessive current flow. Leaving the circuit engerized for 2 minutes allows the coil to warm up. When warm, the coil may open (Amps drop to zero, or short (Amp draw greater than 0.75A).
-
Listen for an audible click when the solenoid operates. This Step checks the ignition feed circuit for an open.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing DTCs use the scan tool Capture Info to record freeze frame and failure records for reference, as data will be lost when Clear Info function is used. Was the On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does Actual EGR respond to scan tool commands? | -- | |||
Is current draw less then the specified value, but not zero? | 0.75 A | |||
4 |
Does DVM display infinite resistance? | -- | ||
5 |
Does test light turn ON and OFF with each command? | -- | ||
6 |
Is the test light ON? | -- | ||
Does the solenoid operate? | -- | |||
8 | DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored refer the applicable DTC table(s) first. Are any additional DTCs stored? | -- | Go to the Applicable DTC Table | Go to Diagnostic Aids |
9 | Check for a poor connection at the EGR solenoid and replace terminals as necessary. Did the terminal require replacement? | -- | ||
10 | Repair EGR solenoid control circuit. Is the action complete? | -- | -- | |
11 | Check for a poor connection at the PCM, EGR control circuit. Was a problem found? | -- | ||
12 | Repair the open in the ignition feed circuit. Is the action complete? | -- | -- | |
13 | Replace the EGR solenoid. Refer to Exhaust Gas Recirculation Solenoid Replacement . Is the action complete? | -- | -- | |
14 | Replace the faulty PCM. Important: If the PCM is faulty, the new PCM must be programmed. Go to Powertrain Control Module Replacement/Programming . Is the action complete ? | -- | -- | |
15 |
Does the scan tool indicate that this diagnostic Ran and Passed? | -- | ||
16 | Using the scan tool, select Capture Info, Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC Table | System OK |
