DTC P1554 Cruise Control Feedback Circuit. Buick Regal 1996

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1996 🢒 Regal 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 DTC P1554 Cruise Control Feedback Circuit

Refer to

VSS, Cruise Control Module

Engine Controls Components
Information Sensors
TCC Brake Switch, TCC Solenoid
IAC Valve, Trans Range
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
.

The powertrain control module (PCM) inhibits cruise control operation when certain conditions are not appropriate for cruise control operation. The PCM removes the ground from the cruise control inhibit signal circuit in order to disengage cruise control operation.

Conditions for Setting the DTC

•	The PCM is commanding the SMCC module to inhibit cruise control operation (Cruise Inhibit circuit not grounded).

•	The Cruise Status circuit signal indicates that cruise control is engaged.

•	Above conditions for longer than 1 second.

Action Taken When the DTC Sets

•	The PCM will not illuminate the malfunction indicator lamp (MIL).

•	The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

•	A 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 Clear Info function.

Diagnostic Aids

Check for the following conditions:

•	Poor connection at PCM. 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, observe the Cruise Status display on the scan tool while moving connectors and wiring harnesses related to the Stepper Motor Cruise Control module. A change in the display will indicate the location of the fault.

If DTC P1554 cannot be duplicated, the information included in the Failure records data can be useful in determining how many ignition cycles have passed since the DTC was last set.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

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.

DTC P1554 - Cruise Control Status Circuit

Step	Action	Value(s)	Yes	No
1	Was the Powertrain On-Board Diagnostic (OBD) System Check performed?	--	Go to Step 2	Go to the Powertrain On Board Diagnostic (OBD) System Check
2	Turn ON the ignition switch. Observe the Cruise Engaged display on the scan tool. Does Cruise Engaged display Yes?	--	Go to Step 3	Go to Step 5
3	Turn OFF the ignition switch. Disconnect the PCM. Turn ON the ignition switch. Using a J 39200 digital multimeter, measure voltage between the cruise status circuit at the PCM harness connector and ground. Is voltage greater than the specified value?	7V	Go to Step 4	Go to Step 9
4	Check the cruise status circuit for a poor connection at the PCM. If a problem is found, replace faulty terminal. Refer to Repair procedures in Electrical Diagnosis. Was a problem found?	--	Go to Step 14	Go to Step 12
5	Turn OFF the ignition switch. Disconnect the stepper motor cruise control module. Turn ON the ignition switch. Probe the cruise inhibit circuit at the stepper motor cruise control module connector with a J 35616-200 test light to B+. Is the test light ON?	--	Go to Step 6	Go to Step 7
6	Turn OFF the ignition switch. Disconnect the PCM and probe the cruise inhibit circuit with a test light to B+. Is the test light ON?	--	Go to Step 13	Go to Step 12
7	Turn OFF the ignition switch. Reconnect the stepper motor cruise control module. Disconnect the PCM. Turn ON the ignition switch. Using a J 39200 Digital Multimeter, measure voltage between the cruise inhibit circuit at the PCM harness connector and ground. Is the voltage near the specified value?	B+	Go to Step 8	Go to Step 11
8	Clear DTC P1554. Start the engine and observe DTC(s). Did DTC P1554 set?	--	Go to Step 12	Refer to DTC P1554 Diagnostic Aids
9	Check the cruise status circuit for an open or short to ground. If a problem is found, repair the cruise status circuit. Refer to Repair procedures in Electrical Diagnosis. Was a problem found?	--	Go to Step 14	Go to Step 10
10	Check the cruise status circuit for a poor connection at the stepper motor cruise control module. If a problem is found, replace faulty terminal. Refer to Repair procedures in Electrical Diagnosis. Was a problem found?	--	Go to Step 14	Go to Step 11
11	Replace the stepper motor cruise control module. Refer to Cruise Control. Is action complete?	--	Go to Step 14	--
12	Replace the PCM. Important:: The replacement PCM must be programmed. Go to Powertrain Control Module Replacement/Programming . Is action complete?	--	Go to Step 14	--
13	Locate and repair short to ground in the cruise inhibit circuit. Refer to Repair procedures in Electrical Diagnosis. Is action complete?	--	Go to Step 14	--
14	Clear DTC P1554. Start the engine and observe DTC(s). Did DTC P1554 set?	--	Go to Step 2	System OK