For 1990-2009 cars
ABS Components
ABS/TCS Schematics
Handling ESD Sensitive Parts Notice
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics

### Circuit Description

The solenoid valve relay supplies power to the solenoid valve coils in the EBCM/EBTCM. The solenoid valve relay, located in the EBCM/EBTCM, is activated whenever the ignition switch is in the RUN position and no faults are present. The solenoid valve relay remains engaged until the ignition is turned OFF or a failure is detected.

### Conditions for Setting the DTC

• | DTC C0121 will set anytime the solenoid valve relay is commanded on and the EBCM/EBTCM does not see battery voltage at the solenoid valves.

• | DTC C0121 will set anytime the EBCM/EBTCM commands the solenoid valve relay off and battery voltage is still present at the solenoid valves.

### Action Taken When the DTC Sets

• | A malfunction DTC stores.

• | The ABS/TCS disables.

• | The amber ABS/TCS indicator(s) turn on.

• | The Red BRAKE Warning indicator turns on.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

• | 100 ignition cycles pass with no DTC(s) detected.

### Diagnostic Aids

• | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

• | Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:

- | Backed out terminals

- | Improper mating

- | Broken locks

- | Improperly formed or damaged terminals

- | Poor terminal-to-wiring connections

- | Physical damage to the wiring harness

• | The following conditions may cause an intermittent malfunction:

- | A poor connection

- | Rubbed-through wire insulation

- | A broken wire inside the insulation

• | If an intermittent malfunction exists refer to Troubleshooting Procedures Cell 4 in Electrical Diagnosis for further diagnosis.

• | The solenoid valve relay is an integral part of the EBCM/EBTCM and is not serviced separately.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step checks for a short to ground in CKT 440.

2. This step checks for an open in CKT 440.

#### DTC C0121 Valve Relay Circuit Malfunction

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 | Inspect the ABS BATT 2 Maxifuse in the Underhood electrical Center 1. Is the fuse OK? | -- | Go to Step 4 | Go to Step 3
3 |

1. Install a new ABS BATT 2 fuse.
2. Inspect the ABS BATT 2 fuse.

Is the fuse OK?

--

Go to Diagnostic System Check

Go to Step 9

4 | Inspect the ABS BATT Minifuse in the Underhood electrical Center 1. Is the fuse OK? | -- | Go to Step 10 | Go to Step 5
5 |

1. Install a new ABS BATT fuse.
2. Inspect the ABS BATT fuse.

Is the fuse OK?

--

Go to Diagnostic System Check

Go to Step 6

6 |

1. Turn the ignition switch to the OFF position.
2. Remove the ABS BATT Minifuse.
3. Disconnect the EBCM/EBTCM connector C1.
4. Connect the J 39700 Universal Pinout Box using the J 39700-530 cable adapter to the EBCM/EBTCM harness connector only.
5. Using the J 39200 DMM, measure the resistance between the J 39700 terminals 14 and 15.

Is the resistance within specifications?

OL (infinite)

Go to Step 7

Go to Step 8

7 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
8 | Repair the short to ground in CKT 440. Refer to Repair Procedures Cell 5 in Electrical Diagnosis. Is the circuit repair complete? | -- | Go to Diagnostic System Check | --
9 | Repair the short to ground in CKT 1802. Refer to Repair Procedures Cell 5 in Electrical Diagnosis. Is the circuit repair complete? | -- | Go to Diagnostic System Check | --
10 | Using the J 39200 DMM, probe between the ABS BATT 2 fuse test terminals and a good ground in order to measure the voltage. Is the voltage within specifications? | Battery voltage | Go to Step 11 | Go to Power Distribution Cell 10 in Electrical Diagnosis
11 | Using the J 39200 DMM, probe between the ABS BATT Minifuse test terminals and a good ground in order to measure the voltage. Is the voltage within specifications? | Battery voltage | Go to Step 13 | Go to Step 12
12 | Repair the open or high resistance in CKT 1802. Refer to Repair Procedures Cell 5 in Electrical Diagnosis. Is the circuit repair complete? | -- | Go to Diagnostic System Check | --
13 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the EBCM/EBTCM connector C1.
3. Connect the J 39700 Universal Pinout Box using the J 39700-530 cable adapter to the EBCM/EBTCM harness connector only.
4. Turn the ignition switch to the RUN position, engine off.
5. Using the J 39200 DMM, measure the voltage at terminal 14 of the J 39700 .

Is the voltage within specifications?

Battery voltage

Go to Step 7

Go to Step 14

14 | Repair the open or high resistance in CKT 440. Refer to Repair Procedures Cell 5 in Electrical Diagnosis. Is the circuit repair complete? | -- | Go to Diagnostic System Check | --