Circuit Description
Ignition voltage is supplied directly to the Reverse Lockout solenoid. The PCM controls the solenoid by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status will change causing the DTC to set.
When the Reverse Lockout solenoid is energized, the transmission can be shifted into reverse. The PCM enables the Reverse Lockout solenoid whenever vehicle speed is below 5 mph. When vehicle speed is above 5 mph, the PCM will de-energize the solenoid, which will prevent the transmission from being shifted into reverse.
Conditions for Setting the DTC
| • | Engine speed greater than 600 RPM. |
| • | The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match. |
| • | Condition must be present for a minimum of 5 seconds. |
Action Taken When the DTC Sets
| • | DTC P1667 will be stored in the PCM memory when the diagnostic runs and fails. |
| • | The Malfunction Indicator Lamp (MIL) will not illuminate. |
| • | The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in Failure Records. |
Conditions for Clearing the MIL/DTC
| • | If no failures are reported by this or any other non-emission related diagnostic. |
| • | A last test failed (Current DTC) will clear when the diagnostic runs and does not fail. |
| • | PCM battery voltage is interrupted. |
| • | Using a Scan tool. |
Diagnostic Aids
| • | Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed. |
| • | Low system voltage can cause this DTC to set. When reviewing captured data, check if a low system voltage condition was present at the time the DTC was stored in memory. |
Test Description
Number(s) below refer to step numbers on the diagnostic table.
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Listen for an audible click when the solenoid operates. Be sure that both the ON and the OFF states are commanded. Repeat the commands as necessary.
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This check can detect a partially shorted coil which would cause excessive current flow. Leaving the circuit energized for 2 minutes allows the coil to warm up. When warm the coil may open (Amps drop to 0), or short (goes above .75 Amp).
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If no trouble is found in the control circuit or the connection at the PCM, the PCM may be faulty, however, this is an extremely unlikely failure.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 |
Does the solenoid turn ON and OFF with each command? | -- | ||
3 |
Does the Current draw measure less than the value shown (but not 0)? | 1.5A | No trouble found. Go to Diagnostic Aids | |
4 |
Does the DVM display infinite resistance. | -- | ||
5 |
Does the test light turn ON and OFF with each command? | -- | ||
6 | With the test light connected to ground, probe the ignition feed circuit in the solenoid harness connector. Does the test light illuminate? | -- | ||
7 |
Does the solenoid operate? | -- | ||
8 | Check the connections at the solenoid. Was a problem found and corrected? | -- | ||
9 | Check the connections at the PCM. Was a problem found and corrected? | -- | ||
10 | Repair faulty solenoid control circuit. Is the repair complete? | -- | -- | |
11 | Repair the faulty solenoid ignition feed circuit. Is the repair complete? | -- | -- | |
12 | Replace the solenoid. Is the replacement complete? | -- | -- | |
13 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Important: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
14 |
Does the scan tool indicate that this test ran and passed? | -- | ||
15 | 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 |
